@@ -1,7 +1,8 @@
11use std::collections::HashMap;
2−use std::hash::{Hash, Hasher};
2+use std::hash::Hash;
33
44use crate::ast::*;
5+use crate::vocab::with_px;
56
67// ---------------------------------------------------------------------------
78// Style collector: deduplicates CSS and assigns class names
@@ -16,56 +17,315 @@ const BREAKPOINTS: &[(&str, &str)] = &[
1617 ("2xl", "1536px"),
1718];
1819
19−/// Generate short CSS class names: a..z, then aa..a9, ba..b9, ..., z9, then
20−/// aaa, ... The first character is always a letter; later ones are drawn from
21−/// [a-z0-9]. The mapping is a bijection, so distinct indices never collide.
22−pub(crate) fn short_class_name(idx: usize) -> String {
23− const REST: &[u8] = b"abcdefghijklmnopqrstuvwxyz0123456789";
24− // Find the name length: 26 names of length 1, 26*36 of length 2, ...
25− let mut n = idx;
26− let mut len = 1;
27− let mut count = 26usize;
28− while n >= count {
29− n -= count;
30− len += 1;
31− count = count.saturating_mul(36);
20+/// The prefix of every generated class (`hl-2k9xq0m`), which keeps them
21+/// out of the author's own class names.
22+pub const CLASS_PREFIX: &str = "hl-";
23+
24+/// How many base-36 digits a class's name has after `hl-`: 7, about 36
25+/// bits of its style's hash, so a site with 10,000 different styles has
26+/// odds of about 6 in 10,000 that two of them share a name, which
27+/// `htmlang build` reports (`class-collision`). Within one file, a style
28+/// whose name is taken takes more digits.
29+pub const CLASS_DIGITS: usize = 7;
30+
31+/// A stable hash of `text`: FNV-1a, then SplitMix64's finalizer, so every
32+/// digit of a name depends on all of the text. It is the same on every
33+/// platform and in every build, unlike `std`'s hasher.
34+pub fn stable_hash(text: &str) -> u64 {
35+ let mut hash: u64 = 0xcbf2_9ce4_8422_2325;
36+ for byte in text.bytes() {
37+ hash ^= u64::from(byte);
38+ hash = hash.wrapping_mul(0x0000_0100_0000_01b3);
39+ }
40+ hash = (hash ^ (hash >> 30)).wrapping_mul(0xbf58_476d_1ce4_e5b9);
41+ hash = (hash ^ (hash >> 27)).wrapping_mul(0x94d0_49bb_1331_11eb);
42+ hash ^ (hash >> 31)
43+}
44+
45+/// `digits` base-36 digits of `hash`: `2k9xq0m`. With 13, all of it.
46+pub fn hash_digits(hash: u64, digits: usize) -> String {
47+ const DIGITS: &[u8] = b"0123456789abcdefghijklmnopqrstuvwxyz";
48+ let mut n = hash;
49+ (0..digits)
50+ .map(|_| {
51+ let digit = DIGITS[(n % 36) as usize] as char;
52+ n /= 36;
53+ digit
54+ })
55+ .collect()
56+}
57+
58+/// A class htmlang generated: its name, and the hash of the style it
59+/// stands for. One style has one name in every file, so a fragment's
60+/// classes mean the same in any page it goes into.
61+#[derive(Clone, Debug, PartialEq, Eq)]
62+pub struct Class {
63+ pub name: String,
64+ pub style: u64,
65+}
66+
67+/// When a style applies: the at-rule prefixes it is under (their ranks,
68+/// see [`crate::vocab::at_rule_rank`], sorted, so `dark:md:` and `md:dark:`
69+/// are one condition) and its selector prefixes, left to right as the
70+/// selector reads (`hover:children:` is `.a:hover > *`).
71+#[derive(Clone, Default, PartialEq, Eq, Hash, Debug)]
72+struct Condition {
73+ at: Vec<usize>,
74+ selector: Vec<String>,
75+}
76+
77+impl Condition {
78+ /// The condition of an attribute's key, and the name after its
79+ /// prefixes.
80+ fn of(key: &str) -> (Condition, &str) {
81+ let (prefixes, name) = crate::vocab::split_prefixes(key);
82+ let mut condition = Condition::default();
83+ for prefix in prefixes {
84+ match crate::vocab::at_rule_rank(prefix) {
85+ Some(rank) => condition.at.push(rank),
86+ None => condition.selector.push(prefix.to_string()),
87+ }
88+ }
89+ condition.at.sort_unstable();
90+ condition.at.dedup();
91+ (condition, name)
92+ }
93+
94+ /// Only the at-rule part: a direction under `hover:` is the one without
95+ /// it.
96+ fn at_only(at: &[usize]) -> Condition {
97+ Condition {
98+ at: at.to_vec(),
99+ selector: Vec::new(),
100+ }
101+ }
102+
103+ /// The styles go on the element's children (`children:`).
104+ fn on_children(&self) -> bool {
105+ self.selector.iter().any(|p| p == crate::vocab::CHILDREN)
106+ }
107+
108+ /// The styles go on the elements of one kind inside the element
109+ /// (`@td:`): where the element prefix is in the selector chain.
110+ fn inside(&self) -> Option<usize> {
111+ self.selector
112+ .iter()
113+ .position(|p| crate::vocab::element_prefix(p).is_some())
114+ }
115+
116+ /// Whether this condition holds wherever `other` does: its at-rules
117+ /// are implied by `other`'s, and it has no selector or `other`'s.
118+ fn holds_at(&self, other: &Condition) -> bool {
119+ (self.selector.is_empty() || self.selector == other.selector)
120+ && self.at.iter().all(|&a| {
121+ other
122+ .at
123+ .iter()
124+ .any(|&b| crate::vocab::at_rule_implied(a, b))
125+ })
126+ }
127+
128+ /// The order the rules of each condition are written in, which the
129+ /// cascade follows: no prefix, then selectors, then each at-rule
130+ /// block (see [`at_order`]), with its selectors inside it.
131+ fn order(&self) -> (AtOrder, SelectorOrder) {
132+ (at_order(&self.at), selector_order(&self.selector))
133+ }
134+}
135+
136+/// Where a block of at-rules is written: after the rules without one; by
137+/// its last (innermost) prefix in the order of
138+/// [`crate::vocab::at_rule_prefixes`] (widths, media, container widths), so
139+/// `md:dark:` comes with `dark:`, after it; then by length.
140+type AtOrder = (bool, usize, usize, Vec<usize>);
141+
142+fn at_order(at: &[usize]) -> AtOrder {
143+ (
144+ !at.is_empty(),
145+ at.last().copied().unwrap_or(0),
146+ at.len(),
147+ at.to_vec(),
148+ )
149+}
150+
151+/// Selector chains in the order of [`crate::vocab::PSEUDOS`] (position,
152+/// then form state, then `hover:`, `focus:`, `active:`, `disabled:`), and
153+/// by their argument's text for the same pseudo-class; a chain before the
154+/// longer ones it starts. A chain through `children:` comes after the
155+/// others, ordered by what follows its last `children:` and then by what
156+/// comes before it: only that tail counts toward its specificity (see
157+/// [`selector`]), so `hover:children:` follows `children:` and wins over it
158+/// on hover.
159+type SelectorOrder = (bool, Vec<(usize, String)>, Vec<(usize, String)>);
160+
161+fn selector_order(selector: &[String]) -> SelectorOrder {
162+ let table = crate::vocab::PSEUDOS;
163+ let ranked = |chain: &[String]| -> Vec<(usize, String)> {
164+ chain
165+ .iter()
166+ .map(|p| {
167+ let name = crate::vocab::pseudo_name(p);
168+ let rank = table
169+ .iter()
170+ .position(|(q, _)| *q == name)
171+ .unwrap_or(table.len());
172+ (rank, p.clone())
173+ })
174+ .collect()
175+ };
176+ match selector.iter().rposition(|p| p == crate::vocab::CHILDREN) {
177+ None => (false, ranked(selector), Vec::new()),
178+ Some(i) => (true, ranked(&selector[i + 1..]), ranked(&selector[..i])),
179+ }
180+}
181+
182+/// The order of the chains through an element prefix (`@td:`, see
183+/// [`scoped_selector`]): by the prefixes before it, which select the root
184+/// of the scope and add nothing to the specificity, so `hover:@td:` comes
185+/// after `@td:` and wins on hover; then by the element; then by the
186+/// prefixes after it.
187+fn inside_order(chain: &[String]) -> (SelectorOrder, String, SelectorOrder) {
188+ let at = chain
189+ .iter()
190+ .position(|p| crate::vocab::element_prefix(p).is_some())
191+ .unwrap_or(chain.len());
192+ (
193+ selector_order(&chain[..at]),
194+ chain.get(at).cloned().unwrap_or_default(),
195+ selector_order(chain.get(at + 1..).unwrap_or_default()),
196+ )
197+}
198+
199+/// The selector for `class` under a chain of selector prefixes, read left
200+/// to right. Everything before the last `children:` goes in `:where()`, so
201+/// a parent's `children:` styles have no specificity, and a child's own
202+/// attributes win over them: `children:hover:` is `:where(.a)>*:hover`,
203+/// `hover:children:` is `:where(.a:hover)>*`.
204+fn selector(class: &str, chain: &[String]) -> String {
205+ let last_children = chain.iter().rposition(|p| p == crate::vocab::CHILDREN);
206+ let mut out = format!(".{}", class);
207+ for (i, prefix) in chain.iter().enumerate() {
208+ if prefix == crate::vocab::CHILDREN {
209+ if Some(i) == last_children {
210+ out = format!(":where({})>*", out);
211+ } else {
212+ out.push_str(">*");
213+ }
214+ } else if let Some(pseudo) = crate::vocab::pseudo_selector(prefix) {
215+ out.push_str(&pseudo);
216+ }
32217 }
33− let mut tail = Vec::with_capacity(len - 1);
34− for _ in 1..len {
35− tail.push(REST[n % 36]);
36− n /= 36;
218+ out
219+}
220+
221+/// The rule for the elements an element prefix picks out inside the
222+/// element with the class `class` (see [`Condition::inside`]): the scope's
223+/// root, from the selector prefixes before it (`hover:@td:` is inside a
224+/// hovered element), and the selector for the elements, from those after
225+/// it (`@td:hover:` is a hovered cell). `:scope td` leaves out the root
226+/// itself, so `@ul [@ul:...]` styles the lists inside, not its own. `None`
227+/// when the name has no tag of its own (the parser reports it).
228+fn scoped_selector(class: &str, chain: &[String], at: usize) -> Option<(String, String)> {
229+ let name = crate::vocab::element_prefix(&chain[at])?;
230+ let tag = ElementKind::from_name(name)?.own_tag()?;
231+ let root = selector(class, &chain[..at]);
232+ let mut target = format!(":scope {}", tag);
233+ for prefix in &chain[at + 1..] {
234+ if let Some(pseudo) = crate::vocab::pseudo_selector(prefix) {
235+ target.push_str(&pseudo);
236+ }
237+ }
238+ Some((root, target))
239+}
240+
241+/// The `@media` or `@container` rule an at-rule prefix stands for, as
242+/// written in readable and in compact output.
243+fn at_rule(rank: usize, dev: bool) -> String {
244+ let prefix = crate::vocab::at_rule_prefixes()
245+ .nth(rank)
246+ .unwrap_or_default();
247+ let name = prefix.trim_end_matches(':');
248+ let width = |name: &str| {
249+ BREAKPOINTS
250+ .iter()
251+ .find(|(n, _)| *n == name)
252+ .map_or("0", |(_, w)| *w)
253+ };
254+ let (kind, feature, value) = if let Some(size) = name.strip_prefix("cq-") {
255+ ("@container", "min-width", width(size))
256+ } else {
257+ match name {
258+ "print" => {
259+ return "@media print".to_string();
260+ }
261+ "dark" => ("@media", "prefers-color-scheme", "dark"),
262+ "motion-safe" => ("@media", "prefers-reduced-motion", "no-preference"),
263+ "motion-reduce" => ("@media", "prefers-reduced-motion", "reduce"),
264+ "landscape" | "portrait" => ("@media", "orientation", name),
265+ _ => ("@media", "min-width", width(name)),
266+ }
267+ };
268+ if dev {
269+ format!("{} ({}: {})", kind, feature, value)
270+ } else {
271+ format!("{}({}:{})", kind, feature, value)
37272 }
38− let mut name = String::with_capacity(len);
39− name.push((b'a' + n as u8) as char);
40− name.extend(tail.iter().rev().map(|&b| b as char));
41− name
273+}
274+
275+/// A style as text, for its hash: the defaults of its element's kind, its
276+/// rules (the at-rules' ranks, the selector prefixes and the declarations
277+/// of each) and the rules keyed on it, each part ended by a character CSS
278+/// doesn't have.
279+fn style_text(defaults: &str, rules: &[(Condition, String)], distinct: &str) -> String {
280+ let mut text = format!("{defaults}\u{1}");
281+ for (condition, body) in rules {
282+ for rank in &condition.at {
283+ text.push_str(&format!("{rank}\u{2}"));
284+ }
285+ text.push('\u{3}');
286+ for prefix in &condition.selector {
287+ text.push_str(prefix);
288+ text.push('\u{2}');
289+ }
290+ text.push('\u{3}');
291+ text.push_str(body);
292+ text.push('\u{1}');
293+ }
294+ text.push_str(distinct);
295+ text
42296}
43297
44298struct StyleEntry {
45299 class_name: String,
46− base: String,
47− /// (CSS selector suffix, css_rules) — e.g. (":hover", "color:red;")
48− pseudo: Vec<(String, String)>,
49− /// Responsive overrides: (breakpoint_prefix, css)
50− responsive: Vec<(String, String)>,
51− /// Dark mode overrides
52− dark: String,
53− /// Print overrides
54− print: String,
55− motion_safe: String,
56− motion_reduce: String,
57− landscape: String,
58− portrait: String,
59− /// Container query overrides: (breakpoint_prefix, css)
60− container: Vec<(String, String)>,
300+ /// The hash of the style, which names the class
301+ style: u64,
302+ /// The defaults of the element's kind (its layout, a heading's
303+ /// `margin:0`, ...), less what its own attributes set. They are written
304+ /// as `:where(.hl-a)` in the layer `hl-kind`, so an element prefix
305+ /// around it (`@h2:`), its parent's `children:` styles and its own
306+ /// attributes, all in later layers, win over them.
307+ defaults: String,
308+ /// The element's rules: under each condition, its declarations, in the
309+ /// order they are written
310+ rules: Vec<(Condition, String)>,
311+ /// What else tells two elements with the same CSS apart: the rules
312+ /// keyed on this class (see [`StyleCollector::keyed`]). Not written.
313+ distinct: String,
61314}
62315
63316struct StyleCollector {
64317 entries: Vec<StyleEntry>,
65− /// Maps a pre-hashed style signature to an index into `entries`.
66− /// Using u64 as the key keeps lookups allocation-free; on the rare case of
67− /// a hash collision we fall back to a full equality check against the entry.
318+ /// Maps a style's hash to its entries (more than one only when two
319+ /// styles hash alike, which the full comparison tells apart).
68320 index: HashMap<u64, Vec<usize>>,
321+ /// The names given, which a style whose name is taken doesn't get
322+ names: std::collections::HashSet<String>,
323+ /// Rules for an element's children, keyed on its class and written in
324+ /// the block of an at-rule condition: `(at-rules, selector, body)`, e.g.
325+ /// `([md], ":where(.a)>.b", "flex:1;")` (see [`Flow`]).
326+ keyed: Vec<(Vec<usize>, String, String)>,
327+ /// The keyed rules already added
328+ keyed_seen: std::collections::HashSet<(Vec<usize>, String, String)>,
69329}
70330
71331impl StyleCollector {
@@ -73,328 +333,282 @@ impl StyleCollector {
73333 StyleCollector {
74334 entries: Vec::new(),
75335 index: HashMap::new(),
336+ names: std::collections::HashSet::new(),
337+ keyed: Vec::new(),
338+ keyed_seen: std::collections::HashSet::new(),
339+ }
340+ }
341+
342+ /// Add a rule for `selector` under the at-rules `at`, once.
343+ fn add_keyed(&mut self, at: Vec<usize>, selector: String, body: String) {
344+ let rule = (at, selector, body);
345+ if self.keyed_seen.insert(rule.clone()) {
346+ self.keyed.push(rule);
76347 }
77348 }
78349
79350 /// Returns a class name for this style combination, or None if all empty.
80− #[allow(clippy::too_many_arguments)]
81351 fn get_class(
82352 &mut self,
83− base: String,
84− pseudo: Vec<(String, String)>,
85− responsive: Vec<(String, String)>,
86− dark: String,
87− print: String,
88− motion_safe: String,
89− motion_reduce: String,
90− landscape: String,
91− portrait: String,
92− container: Vec<(String, String)>,
353+ defaults: String,
354+ mut rules: Vec<(Condition, String)>,
355+ distinct: String,
93356 ) -> Option<String> {
94− if base.is_empty()
95− && pseudo.is_empty()
96− && responsive.is_empty()
97− && dark.is_empty()
98− && print.is_empty()
99− && motion_safe.is_empty()
100− && motion_reduce.is_empty()
101− && landscape.is_empty()
102− && portrait.is_empty()
103− && container.is_empty()
104− {
357+ rules.retain(|(_, body)| !body.is_empty());
358+ if defaults.is_empty() && rules.is_empty() {
105359 return None;
106360 }
107− use std::collections::hash_map::DefaultHasher;
108− let mut h = DefaultHasher::new();
109− base.hash(&mut h);
110− pseudo.hash(&mut h);
111− responsive.hash(&mut h);
112− dark.hash(&mut h);
113− print.hash(&mut h);
114− motion_safe.hash(&mut h);
115− motion_reduce.hash(&mut h);
116− landscape.hash(&mut h);
117− portrait.hash(&mut h);
118− container.hash(&mut h);
119− let sig = h.finish();
120−
121− if let Some(indices) = self.index.get(&sig) {
361+ rules.sort_by_cached_key(|(condition, _)| condition.order());
362+ let style = stable_hash(&style_text(&defaults, &rules, &distinct));
363+
364+ if let Some(indices) = self.index.get(&style) {
122365 for &idx in indices {
123366 let e = &self.entries[idx];
124− if e.base == base
125− && e.pseudo == pseudo
126− && e.responsive == responsive
127− && e.dark == dark
128− && e.print == print
129− && e.motion_safe == motion_safe
130− && e.motion_reduce == motion_reduce
131− && e.landscape == landscape
132− && e.portrait == portrait
133− && e.container == container
134− {
367+ if e.defaults == defaults && e.rules == rules && e.distinct == distinct {
135368 return Some(e.class_name.clone());
136369 }
137370 }
138371 }
372+ // The name is the hash's first digits, and more of them when
373+ // another style of this file has those; after all 13, the entry's
374+ // number tells the two apart
139375 let idx = self.entries.len();
140− let name = short_class_name(idx);
376+ let name = (CLASS_DIGITS..=13)
377+ .map(|digits| format!("{}{}", CLASS_PREFIX, hash_digits(style, digits)))
378+ .find(|name| !self.names.contains(name))
379+ .unwrap_or_else(|| format!("{}{}{}", CLASS_PREFIX, hash_digits(style, 13), idx));
380+ self.names.insert(name.clone());
141381 self.entries.push(StyleEntry {
142382 class_name: name.clone(),
143− base,
144− pseudo,
145− responsive,
146− dark,
147− print,
148− motion_safe,
149− motion_reduce,
150− landscape,
151− portrait,
152− container,
383+ style,
384+ defaults,
385+ rules,
386+ distinct,
153387 });
154− self.index.entry(sig).or_default().push(idx);
388+ self.index.entry(style).or_default().push(idx);
155389 Some(name)
156390 }
157391
158− fn to_css_formatted(&self, dev: bool, use_layer: bool) -> String {
159− let mut css = String::new();
160− let inner_indent = if use_layer && dev { " " } else { "" };
392+ /// The classes given, in the order they were
393+ fn classes(&self) -> impl Iterator<Item = Class> + '_ {
394+ self.entries.iter().map(|e| Class {
395+ name: e.class_name.clone(),
396+ style: e.style,
397+ })
398+ }
161399
162− // Wrap in @layer for specificity management
163− if use_layer {
400+ /// All generated rules, in three layers (see [`LAYERS`]): the element
401+ /// kinds' defaults in `hl-kind` (`:where(.hl-a)`), the rules for the
402+ /// elements an element prefix picks out inside an element (`@td:`), and
403+ /// a function's scoped `@style`, in `hl-inside`, and the elements' own
404+ /// rules in `htmlang`. They are written in a fixed order, so which rule
405+ /// wins never depends on where in the page an element is: the rules
406+ /// without a prefix, then those under selector prefixes, then each block
407+ /// of at-rules (see [`at_order`]), in which the rules keyed on a parent
408+ /// come first, then the element's own, then its selectors (see
409+ /// [`selector_order`]).
410+ fn to_css_formatted(&self, dev: bool, scoped: &[String]) -> String {
411+ // The defaults: `:where(.hl-a,.hl-b){...}`
412+ let mut kind = String::new();
413+ let mut defaults: Vec<(&str, Vec<&str>)> = Vec::new();
414+ for e in self.entries.iter().filter(|e| !e.defaults.is_empty()) {
415+ match defaults.iter_mut().find(|(body, _)| *body == e.defaults) {
416+ Some((_, classes)) => classes.push(&e.class_name),
417+ None => defaults.push((&e.defaults, vec![&e.class_name])),
418+ }
419+ }
420+ for (body, classes) in defaults {
421+ let classes: Vec<String> = classes.iter().map(|c| format!(".{}", c)).collect();
422+ let selector = format!(":where({})", classes.join(","));
164423 if dev {
165− css.push_str("@layer htmlang {\n");
424+ kind.push_str(&format!(" {} {{{}}}\n", selector, body));
166425 } else {
167− css.push_str("@layer htmlang{");
426+ kind.push_str(&format!("{}{{{}}}", selector, body));
168427 }
169428 }
170429
171− // Non-responsive rules. Base and pseudo rules are merged separately by
172− // identical body so that e.g. `.a,.b{display:flex;flex-direction:column;}`
173− // replaces two identical rules. Pseudo variants are grouped per selector
174− // suffix (`:hover` with `:hover`, etc.) to keep each pseudo's cascade
175− // position independent of others.
176− let mut base_pairs: Vec<(&str, &str)> = Vec::with_capacity(self.entries.len());
177− for e in &self.entries {
178− if !e.base.is_empty() {
179− base_pairs.push((e.class_name.as_str(), e.base.as_str()));
430+ let mut inside = self.blocks(true, dev);
431+ // A function's scoped `@style`, nested under its class
432+ for block in scoped {
433+ if dev {
434+ inside.push_str(block);
435+ inside.push('\n');
436+ } else {
437+ inside.push_str(&compact_css(block));
180438 }
181439 }
182− emit_grouped_rules(&mut css, &base_pairs, "", inner_indent, dev);
183−
184− // Collect pseudo rules grouped by selector suffix, preserving the order
185− // in which suffixes first appear across entries.
186− let mut pseudo_order: Vec<&str> = Vec::new();
187− let mut pseudo_buckets: HashMap<&str, Vec<(&str, &str)>> = HashMap::new();
188− for e in &self.entries {
189− for (selector, body) in &e.pseudo {
190− if body.is_empty() {
191− continue;
192− }
193− let key = selector.as_str();
194− if !pseudo_buckets.contains_key(key) {
195− pseudo_order.push(key);
196− }
197− pseudo_buckets
198− .entry(key)
199− .or_default()
200− .push((e.class_name.as_str(), body.as_str()));
440+
441+ let mut css = String::new();
442+ for (name, rules) in [
443+ ("hl-kind", kind),
444+ ("hl-inside", inside),
445+ ("htmlang", self.blocks(false, dev)),
446+ ] {
447+ if rules.is_empty() {
448+ continue;
201449 }
202− }
203− for selector in &pseudo_order {
204− if let Some(pairs) = pseudo_buckets.get(selector) {
205− emit_grouped_rules(&mut css, pairs, selector, inner_indent, dev);
450+ if dev {
451+ css.push_str(&format!("@layer {} {{\n{}}}\n", name, rules));
452+ } else {
453+ css.push_str(&format!("@layer {}{{{}}}", name, rules));
206454 }
207455 }
456+ css
457+ }
208458
209− // Responsive rules grouped by breakpoint
210− for &(bp_name, bp_width) in BREAKPOINTS {
211− let mut bp_pairs: Vec<(&str, &str)> = Vec::new();
212− for e in &self.entries {
213− for (bp, rule_css) in &e.responsive {
214− if bp == bp_name && !rule_css.is_empty() {
215− bp_pairs.push((e.class_name.as_str(), rule_css.as_str()));
459+ /// The rules of every block of at-rules, in order: those for the
460+ /// elements inside (`inside`: rules under an element prefix, each in
461+ /// an `@scope` on its element's class), or the elements' own.
462+ fn blocks(&self, inside: bool, dev: bool) -> String {
463+ let mut css = String::new();
464+ let rules = || {
465+ self.entries.iter().flat_map(move |e| {
466+ e.rules
467+ .iter()
468+ .filter(move |(c, _)| c.inside().is_some() == inside)
469+ .map(move |(c, body)| (e, c, body))
470+ })
471+ };
472+ let mut blocks: Vec<&[usize]> = vec![&[]];
473+ let keyed = self.keyed.iter().filter(|_| !inside);
474+ let every = rules()
475+ .map(|(_, c, _)| c.at.as_slice())
476+ .chain(keyed.map(|(at, _, _)| at.as_slice()));
477+ for at in every {
478+ if !blocks.contains(&at) {
479+ blocks.push(at);
480+ }
481+ }
482+ blocks.sort_by_key(|at| at_order(at));
483+
484+ for at in blocks {
485+ let depth = at.len();
486+ // Readable output indents a rule inside `@layer` and inside
487+ // each at-rule but the first
488+ let indent = if dev {
489+ " ".repeat(depth.max(1))
490+ } else {
491+ String::new()
492+ };
493+ let mut inner = String::new();
494+ // Rules keyed on a parent's class come first: they have the
495+ // specificity of one class, like a class rule, so the child's
496+ // own rules in the block still win
497+ if !inside {
498+ let keyed: Vec<(&str, &str)> = self
499+ .keyed
500+ .iter()
501+ .filter(|(a, _, _)| a.as_slice() == at)
502+ .map(|(_, selector, body)| (selector.as_str(), body.as_str()))
503+ .collect();
504+ emit_selector_rules(&mut inner, &keyed, &indent, dev);
505+ }
506+ // The selector chains of this block, in order
507+ let mut chains: Vec<&[String]> = Vec::new();
508+ for (_, condition, _) in rules() {
509+ if condition.at == at && !chains.contains(&condition.selector.as_slice()) {
510+ chains.push(&condition.selector);
511+ }
512+ }
513+ if inside {
514+ chains.sort_by_cached_key(|chain| inside_order(chain));
515+ // One `@scope` for each root, its rules in the order of
516+ // the chains: rules for one element under two roots (`.a`
517+ // and `.a:hover`) tie on specificity and proximity, so the
518+ // later one wins
519+ let mut scopes: Vec<(String, Vec<(String, &str)>)> = Vec::new();
520+ for chain in chains {
521+ let Some(element) = chain
522+ .iter()
523+ .position(|p| crate::vocab::element_prefix(p).is_some())
524+ else {
525+ continue;
526+ };
527+ for (e, _, body) in
528+ rules().filter(|(_, c, _)| c.at == at && c.selector == chain)
529+ {
530+ let Some((root, target)) = scoped_selector(&e.class_name, chain, element)
531+ else {
532+ continue;
533+ };
534+ match scopes.iter_mut().find(|(r, _)| *r == root) {
535+ Some((_, targets)) => targets.push((target, body)),
536+ None => scopes.push((root, vec![(target, body)])),
537+ }
216538 }
217539 }
218− }
219− emit_media_block(
220− &mut css,
221− &format!("@media (min-width: {})", bp_width),
222− &format!("@media(min-width:{})", bp_width),
223− &bp_pairs,
224− "",
225− dev,
226− );
227− }
228−
229− // Dark mode rules
230− let dark_pairs: Vec<(&str, &str)> = self
231− .entries
232− .iter()
233− .filter(|e| !e.dark.is_empty())
234− .map(|e| (e.class_name.as_str(), e.dark.as_str()))
235− .collect();
236− emit_media_block(
237− &mut css,
238− "@media (prefers-color-scheme: dark)",
239− "@media(prefers-color-scheme:dark)",
240− &dark_pairs,
241− "",
242− dev,
243− );
244−
245− // Print rules
246− let print_pairs: Vec<(&str, &str)> = self
247− .entries
248− .iter()
249− .filter(|e| !e.print.is_empty())
250− .map(|e| (e.class_name.as_str(), e.print.as_str()))
251− .collect();
252− emit_media_block(
253− &mut css,
254− "@media print",
255− "@media print",
256− &print_pairs,
257− "",
258− dev,
259− );
260−
261− // Motion safe rules
262− let motion_safe_pairs: Vec<(&str, &str)> = self
263− .entries
264− .iter()
265− .filter(|e| !e.motion_safe.is_empty())
266− .map(|e| (e.class_name.as_str(), e.motion_safe.as_str()))
267− .collect();
268− emit_media_block(
269− &mut css,
270− "@media (prefers-reduced-motion: no-preference)",
271− "@media(prefers-reduced-motion:no-preference)",
272− &motion_safe_pairs,
273− "",
274− dev,
275− );
276−
277− // Motion reduce rules
278− let motion_reduce_pairs: Vec<(&str, &str)> = self
279− .entries
280− .iter()
281− .filter(|e| !e.motion_reduce.is_empty())
282− .map(|e| (e.class_name.as_str(), e.motion_reduce.as_str()))
283− .collect();
284− emit_media_block(
285− &mut css,
286− "@media (prefers-reduced-motion: reduce)",
287− "@media(prefers-reduced-motion:reduce)",
288− &motion_reduce_pairs,
289− "",
290− dev,
291− );
292−
293− // Landscape rules
294− let landscape_pairs: Vec<(&str, &str)> = self
295− .entries
296− .iter()
297− .filter(|e| !e.landscape.is_empty())
298− .map(|e| (e.class_name.as_str(), e.landscape.as_str()))
299− .collect();
300− emit_media_block(
301− &mut css,
302− "@media (orientation: landscape)",
303− "@media(orientation:landscape)",
304− &landscape_pairs,
305− "",
306− dev,
307− );
308−
309− // Portrait rules
310− let portrait_pairs: Vec<(&str, &str)> = self
311− .entries
312− .iter()
313− .filter(|e| !e.portrait.is_empty())
314− .map(|e| (e.class_name.as_str(), e.portrait.as_str()))
315− .collect();
316− emit_media_block(
317− &mut css,
318− "@media (orientation: portrait)",
319− "@media(orientation:portrait)",
320− &portrait_pairs,
321− "",
322− dev,
323− );
324−
325− // Container query rules grouped by breakpoint
326− for &(bp_name, bp_width) in BREAKPOINTS {
327− let mut cq_pairs: Vec<(&str, &str)> = Vec::new();
328− for e in &self.entries {
329− for (bp, rule_css) in &e.container {
330− if bp == bp_name && !rule_css.is_empty() {
331− cq_pairs.push((e.class_name.as_str(), rule_css.as_str()));
332− }
540+ let inner_indent = if dev {
541+ format!("{} ", indent)
542+ } else {
543+ String::new()
544+ };
545+ for (root, targets) in scopes {
546+ let targets: Vec<(&str, &str)> =
547+ targets.iter().map(|(t, b)| (t.as_str(), *b)).collect();
548+ inner.push_str(&indent);
549+ inner.push_str(&format!("@scope ({})", root));
550+ inner.push_str(if dev { " {\n" } else { "{" });
551+ emit_selector_rules(&mut inner, &targets, &inner_indent, dev);
552+ inner.push_str(&indent);
553+ inner.push_str(if dev { "}\n" } else { "}" });
333554 }
334− }
335− emit_media_block(
336− &mut css,
337− &format!("@container (min-width: {})", bp_width),
338− &format!("@container(min-width:{})", bp_width),
339− &cq_pairs,
340− "",
341− dev,
342− );
343− }
344−
345− // Close @layer
346− if use_layer {
347− if dev {
348− css.push_str("}\n");
349555 } else {
350− css.push('}');
556+ chains.sort_by_cached_key(|chain| selector_order(chain));
557+ for chain in chains {
558+ let pairs: Vec<(String, &str)> = rules()
559+ .filter(|(_, c, _)| c.at == at && c.selector == chain)
560+ .map(|(e, _, body)| (selector(&e.class_name, chain), body.as_str()))
561+ .collect();
562+ emit_grouped_rules(&mut inner, &pairs, &indent, dev);
563+ }
564+ }
565+ if inner.is_empty() {
566+ continue;
351567 }
568+ // Each at-rule wraps the next, outermost first
569+ for (level, &rank) in at.iter().enumerate().rev() {
570+ let pad = if dev {
571+ " ".repeat(level)
572+ } else {
573+ String::new()
574+ };
575+ inner = if dev {
576+ format!("{pad}{} {{\n{inner}{pad}}}\n", at_rule(rank, true))
577+ } else {
578+ format!("{}{{{inner}}}", at_rule(rank, false))
579+ };
580+ }
581+ css.push_str(&inner);
352582 }
353−
354583 css
355584 }
356585}
357586
358−/// Emit CSS rules from `(class_name, body)` pairs, merging identical bodies
587+/// Emit CSS rules from `(selector, body)` pairs, merging identical bodies
359588/// into a single selector-list rule (e.g. `.a,.b{body}`). The first occurrence
360589/// of each distinct body determines ordering, so output stays deterministic
361−/// across runs. `selector_suffix` is appended to each class (e.g. `":hover"`,
362−/// or `""` for plain class rules). `indent` is prepended to each rule line.
363−fn emit_grouped_rules(
364− out: &mut String,
365− pairs: &[(&str, &str)],
366− selector_suffix: &str,
367− indent: &str,
368− dev: bool,
369−) {
590+/// across runs. `indent` is prepended to each rule line.
591+fn emit_grouped_rules(out: &mut String, pairs: &[(String, &str)], indent: &str, dev: bool) {
370592 if pairs.is_empty() {
371593 return;
372594 }
373595 // Group in first-occurrence order.
374596 let mut order: Vec<&str> = Vec::new();
375597 let mut groups: HashMap<&str, Vec<&str>> = HashMap::new();
376− for &(name, body) in pairs {
598+ for (selector, body) in pairs {
377599 if body.is_empty() {
378600 continue;
379601 }
380602 if !groups.contains_key(body) {
381603 order.push(body);
382604 }
383− groups.entry(body).or_default().push(name);
605+ groups.entry(body).or_default().push(selector);
384606 }
385607 let sp = if dev { " " } else { "" };
386608 let nl = if dev { "\n" } else { "" };
387609 for body in &order {
388− let names = &groups[body];
389610 out.push_str(indent);
390− for (i, n) in names.iter().enumerate() {
391− if i > 0 {
392− out.push(',');
393− }
394− out.push('.');
395− out.push_str(n);
396− out.push_str(selector_suffix);
397− }
611+ out.push_str(&groups[body].join(","));
398612 out.push_str(sp);
399613 out.push('{');
400614 out.push_str(body);
@@ -403,38 +617,44 @@ fn emit_grouped_rules(
403617 }
404618}
405619
406−/// Emit an `@media` / `@container` block containing grouped class rules.
407−/// Skips the block entirely if no non-empty bodies are present.
408−fn emit_media_block(
409− out: &mut String,
410− header_dev: &str,
411− header_min: &str,
412− pairs: &[(&str, &str)],
413− selector_suffix: &str,
414− dev: bool,
415−) {
416− if pairs.iter().all(|(_, body)| body.is_empty()) {
417− return;
418− }
419− let mut inner = String::new();
420− let inner_indent = if dev { " " } else { "" };
421− emit_grouped_rules(&mut inner, pairs, selector_suffix, inner_indent, dev);
422− if inner.is_empty() {
423− return;
424− }
425− if dev {
426− out.push_str(&format!("{} {{\n{}}}\n", header_dev, inner));
427− } else {
428− out.push_str(&format!("{}{{{}}}", header_min, inner));
620+/// Emit `(selector, body)` rules in their order, merging a run of rules
621+/// with the same body into one rule with a selector list (the order
622+/// matters: two rules may apply to one element).
623+fn emit_selector_rules(out: &mut String, rules: &[(&str, &str)], indent: &str, dev: bool) {
624+ let mut i = 0;
625+ while i < rules.len() {
626+ let body = rules[i].1;
627+ let run = rules[i..].iter().take_while(|(_, b)| *b == body).count();
628+ if !body.is_empty() {
629+ let selectors: Vec<&str> = rules[i..i + run].iter().map(|(s, _)| *s).collect();
630+ out.push_str(indent);
631+ out.push_str(&selectors.join(","));
632+ if dev {
633+ out.push(' ');
634+ }
635+ out.push('{');
636+ out.push_str(body);
637+ out.push('}');
638+ if dev {
639+ out.push('\n');
640+ }
641+ }
642+ i += run;
429643 }
430644}
431645
432646struct GenContext {
433647 dev: bool,
434648 depth: usize,
435− image_count: usize,
436649 has_interactive: bool,
437− has_defer: bool,
650+ /// Writing inside a text element, at any depth: htmlang's own `<div>`s
651+ /// are `<span>`s there, which text can hold.
652+ in_text: bool,
653+ /// How the element whose children are being written lays them out
654+ flow: Flow,
655+ /// Writing the children of a `@picture`, where `@source`'s leading
656+ /// argument is its `srcset`
657+ in_picture: bool,
438658}
439659
440660impl GenContext {
@@ -460,23 +680,26 @@ pub struct CodegenOptions {
460680 pub dev: bool,
461681 pub partial: bool,
462682 pub minify: bool,
463− pub compat: bool,
464683}
465684
466685/// Generate HTML from a parsed document using the given options.
467686pub fn generate_with(doc: &Document, opts: &CodegenOptions) -> String {
687+ generate_with_classes(doc, opts).0
688+}
689+
690+/// [`generate_with`], and the classes the document's styles were given,
691+/// for a check across files that no name stands for two styles.
692+pub fn generate_with_classes(doc: &Document, opts: &CodegenOptions) -> (String, Vec<Class>) {
693+ let mut classes = Vec::new();
468694 let mut html = if opts.partial {
469− generate_partial_inner(doc, opts.dev)
695+ generate_partial_inner(doc, opts.dev, &mut classes)
470696 } else {
471− generate_full_inner(doc, opts.dev)
697+ generate_full_inner(doc, opts.dev, &mut classes)
472698 };
473699 if opts.minify {
474700 html = minify_html(&html);
475701 }
476− if opts.compat {
477− html = add_vendor_prefixes(&html);
478− }
479− html
702+ (html, classes)
480703}
481704
482705pub fn generate(doc: &Document) -> String {
@@ -524,38 +747,6 @@ pub fn generate_minified(doc: &Document) -> String {
524747 )
525748}
526749
527−pub fn generate_compat(doc: &Document) -> String {
528− generate_with(
529− doc,
530− &CodegenOptions {
531− compat: true,
532− ..Default::default()
533− },
534− )
535−}
536−
537−pub fn generate_dev_compat(doc: &Document) -> String {
538− generate_with(
539− doc,
540− &CodegenOptions {
541− dev: true,
542− compat: true,
543− ..Default::default()
544− },
545− )
546−}
547−
548−pub fn generate_minified_compat(doc: &Document) -> String {
549− generate_with(
550− doc,
551− &CodegenOptions {
552− minify: true,
553− compat: true,
554− ..Default::default()
555− },
556− )
557−}
558−
559750fn minify_html(html: &str) -> String {
560751 let mut result = String::with_capacity(html.len());
561752 let mut in_pre = false;
@@ -634,514 +825,132 @@ fn minify_html(html: &str) -> String {
634825 result
635826}
636827
637−/// Add vendor prefixes to CSS within <style> tags for broader browser compatibility.
638−fn add_vendor_prefixes(html: &str) -> String {
639− // Find CSS within <style>...</style> and add vendor prefixes
640− let mut result = String::with_capacity(html.len() + 512);
641− let mut rest = html;
642− while let Some(start) = rest.find("<style>") {
643− let after_tag = start + 7;
644− result.push_str(&rest[..after_tag]);
645− rest = &rest[after_tag..];
646− if let Some(end) = rest.find("</style>") {
647− let css = &rest[..end];
648− result.push_str(&prefix_css(css));
649− result.push_str("</style>");
650− rest = &rest[end + 8..];
651− } else {
652− break;
653− }
654− }
655− result.push_str(rest);
656− result
657−}
658−
659−fn prefix_css(css: &str) -> String {
660− let mut out = String::with_capacity(css.len() + 256);
661− let mut i = 0;
662− let bytes = css.as_bytes();
663− while i < bytes.len() {
664− // Find property declarations
665− if let Some(pos) = css[i..].find('{') {
666− let brace = i + pos;
667− out.push_str(&css[i..=brace]);
668− i = brace + 1;
669− // Process declarations within this block
670− if let Some(close) = css[i..].find('}') {
671− let block = &css[i..i + close];
672− out.push_str(&prefix_declarations(block));
673− out.push('}');
674− i = i + close + 1;
675− }
676− } else {
677− out.push_str(&css[i..]);
678− break;
679− }
680− }
681− out
682−}
683−
684−fn prefix_declarations(block: &str) -> String {
685− let mut out = String::with_capacity(block.len() + 128);
686− for decl in block.split(';') {
687− let decl = decl.trim();
688− if decl.is_empty() {
689− continue;
690− }
691− if let Some((prop, val)) = decl.split_once(':') {
692− let prop = prop.trim();
693− let val = val.trim();
694− match prop {
695− "backdrop-filter" => {
696− out.push_str(&format!("-webkit-backdrop-filter:{};", val));
697− out.push_str(&format!("backdrop-filter:{};", val));
698− }
699− "user-select" => {
700− out.push_str(&format!("-webkit-user-select:{};", val));
701− out.push_str(&format!("-moz-user-select:{};", val));
702− out.push_str(&format!("user-select:{};", val));
703− }
704− "appearance" => {
705− out.push_str(&format!("-webkit-appearance:{};", val));
706− out.push_str(&format!("-moz-appearance:{};", val));
707− out.push_str(&format!("appearance:{};", val));
708− }
709− "background-clip" if val.contains("text") => {
710− out.push_str(&format!("-webkit-background-clip:{};", val));
711− out.push_str(&format!("background-clip:{};", val));
712− }
713− "hyphens" => {
714− out.push_str(&format!("-webkit-hyphens:{};", val));
715− out.push_str(&format!("-ms-hyphens:{};", val));
716− out.push_str(&format!("hyphens:{};", val));
717− }
718− "text-size-adjust" => {
719− out.push_str(&format!("-webkit-text-size-adjust:{};", val));
720− out.push_str(&format!("-ms-text-size-adjust:{};", val));
721− out.push_str(&format!("text-size-adjust:{};", val));
722− }
723− "mask-image" | "mask-size" | "mask-repeat" | "mask-position" => {
724− out.push_str(&format!("-webkit-{}:{};", prop, val));
725− out.push_str(&format!("{}:{};", prop, val));
726− }
727− _ => {
728− out.push_str(decl);
729− out.push(';');
730− }
731− }
732− } else {
733− out.push_str(decl);
734− out.push(';');
735− }
736− }
737− out
738−}
739−
740−fn generate_full_inner(doc: &Document, dev: bool) -> String {
828+fn generate_full_inner(doc: &Document, dev: bool, classes: &mut Vec<Class>) -> String {
829+ // Without `@page` the output is a fragment
830+ let Some(page) = &doc.page else {
831+ return generate_partial_inner(doc, dev, classes);
832+ };
741833 let mut styles = StyleCollector::new();
742834 let mut ctx = GenContext {
743835 dev,
744836 depth: 0,
745− image_count: 0,
746837 has_interactive: false,
747− has_defer: false,
838+ in_text: false,
839+ flow: Flow::default(),
840+ in_picture: false,
748841 };
749842
750− // Check if document has @main for skip-to-content link
751− let has_main = has_element_kind(&doc.nodes, &ElementKind::Main);
843+ // The page is the root element: `<body>` is a column (the reset makes
844+ // it one, filling the viewport), `@page`'s styles are its class, and
845+ // the page's top-level elements are its children
846+ let root = Element {
847+ kind: ElementKind::El,
848+ attrs: page.styles.clone(),
849+ argument: None,
850+ children: Vec::new(),
851+ line_num: 0,
852+ function: None,
853+ };
854+ let mut own = Flow::of(&root);
855+ let top = Flow::default();
856+ let site = Site {
857+ kind: &root.kind,
858+ parent: &top,
859+ has_overlay_children: holds_overlays(&doc.nodes),
860+ inline: false,
861+ root: true,
862+ };
863+ let body_class = element_class(&root, &site, &mut styles);
864+ own.class = body_class.clone();
865+ ctx.flow = own;
752866
753867 let mut body = String::new();
868+ generate_children(
869+ &doc.nodes,
870+ Some(Layout::Column),
871+ &mut body,
872+ &mut styles,
873+ &mut ctx,
874+ );
754875
755− // Skip-to-content link for accessibility (only when @main exists)
756− if has_main {
757− if dev {
758− body.push_str("<a href=\"#hl-main\" class=\"hl-skip\">Skip to content</a>\n");
759− } else {
760− body.push_str("<a href=\"#hl-main\" class=\"hl-skip\">Skip to content</a>");
761− }
762− }
876+ let element_css = build_element_css(doc, &styles, dev);
877+ let nl = if dev { "\n" } else { "" };
763878
764− for node in &doc.nodes {
765− generate_node(node, None, &mut body, &mut styles, &mut ctx);
879+ let mut meta_html = String::new();
880+ // A `@meta viewport` of the page's own replaces the usual one
881+ if !doc.meta_tags.iter().any(|(name, _)| name == "viewport") {
882+ meta_html.push_str(&format!(
883+ "<meta name=\"viewport\" content=\"width=device-width, initial-scale=1\">{}",
884+ nl
885+ ));
886+ }
887+ meta_html.push_str(&format!(
888+ "<title>{}</title>{}",
889+ html_escape(&page.title),
890+ nl
891+ ));
892+ for (name, content) in &doc.meta_tags {
893+ meta_html.push_str(&format!(
894+ "<meta name=\"{}\" content=\"{}\">{}",
895+ html_escape(name),
896+ html_escape(content),
897+ nl
898+ ));
899+ }
900+ for (property, content) in &doc.og_tags {
901+ meta_html.push_str(&format!(
902+ "<meta property=\"og:{}\" content=\"{}\">{}",
903+ html_escape(property),
904+ html_escape(content),
905+ nl
906+ ));
907+ }
908+ if let Some(path) = &page.favicon {
909+ meta_html.push_str(&format!(
910+ "<link rel=\"icon\" href=\"{}\">{}",
911+ html_escape(path),
912+ nl
913+ ));
914+ }
915+ for block in &doc.head_blocks {
916+ meta_html.push_str(block);
917+ meta_html.push_str(nl);
766918 }
767919
768− // Collect external domains for DNS prefetch
769− let dns_prefetch_html = collect_dns_prefetch(&body, dev);
770−
771− let element_css = build_element_css(doc, &styles, dev);
920+ // `@page`'s HTML attributes go on `<html>`
921+ let mut root_attrs = String::new();
922+ for attr in html_attrs(&page.html_attrs) {
923+ push_html_attr(&mut root_attrs, attr);
924+ }
925+ let mut body_attrs = String::new();
926+ emit_class_attr(&mut body_attrs, body_class.as_deref(), None);
772927
773− // Build meta tags string
774− let meta_html = if doc.meta_tags.is_empty() {
775− String::new()
776− } else {
777− let mut m = String::new();
778− for (name, content) in &doc.meta_tags {
779− if dev {
780− m.push_str(&format!(
781− "<meta name=\"{}\" content=\"{}\">\n",
782− html_escape(name),
783− html_escape(content)
784− ));
785− } else {
786− m.push_str(&format!(
787− "<meta name=\"{}\" content=\"{}\">",
788− html_escape(name),
789− html_escape(content)
790− ));
791− }
928+ // Focus-visible CSS for interactive elements (accessibility)
929+ let focus_visible_css = if ctx.has_interactive {
930+ let focusable = ":where(a,button,input,select,textarea):focus-visible";
931+ if dev {
932+ format!(
933+ "{}{} {{ outline: 2px solid currentColor; outline-offset: 2px; }}\n",
934+ OWN_ELEMENTS, focusable
935+ )
936+ } else {
937+ format!(
938+ "{}{}{{outline:2px solid currentColor;outline-offset:2px}}",
939+ OWN_ELEMENTS, focusable
940+ )
792941 }
793− m
794− };
795−
796− // Build OG meta tags
797− let og_html = if doc.og_tags.is_empty() {
798− String::new()
799942 } else {
800− let mut o = String::new();
801− for (property, content) in &doc.og_tags {
802− if dev {
803− o.push_str(&format!(
804− "<meta property=\"og:{}\" content=\"{}\">\n",
805− html_escape(property),
806− html_escape(content)
807− ));
808− } else {
809− o.push_str(&format!(
810− "<meta property=\"og:{}\" content=\"{}\">",
811− html_escape(property),
812− html_escape(content)
813− ));
814− }
815− }
816− o
817− };
818−
819− // Build head blocks string
820− let head_html = if doc.head_blocks.is_empty() {
821943 String::new()
822− } else {
823− let mut h = String::new();
824− for block in &doc.head_blocks {
825− h.push_str(block);
826− if dev {
827− h.push('\n');
828− }
829− }
830− h
831− };
832−
833− let lang_attr = match &doc.lang {
834− Some(lang) => format!(" lang=\"{}\"", html_escape(lang)),
835− None => String::new(),
836944 };
945+ let reset_css = reset_css(dev, true, &focus_visible_css);
946+ classes.extend(styles.classes());
837947
838− let favicon_html = match &doc.favicon {
839− Some(path) => {
840− // Try to read and inline the favicon
841− if let Ok(data) = std::fs::read(path) {
842− let mime = if path.ends_with(".ico") {
843− "image/x-icon"
844− } else if path.ends_with(".png") {
845− "image/png"
846− } else if path.ends_with(".svg") {
847− "image/svg+xml"
848− } else {
849− "image/x-icon"
850− };
851− let b64 = base64_encode(&data);
852− if dev {
853− format!(
854− "<link rel=\"icon\" href=\"data:{};base64,{}\">\n",
855− mime, b64
856− )
857− } else {
858− format!("<link rel=\"icon\" href=\"data:{};base64,{}\">", mime, b64)
859− }
860− } else {
861− // Fall back to href
862− if dev {
863− format!("<link rel=\"icon\" href=\"{}\">\n", html_escape(path))
864− } else {
865− format!("<link rel=\"icon\" href=\"{}\">", html_escape(path))
866− }
867− }
868− }
869− None => String::new(),
870− };
871−
872− // Canonical URL
873− let canonical_html = match &doc.canonical {
874− Some(url) => {
875− if dev {
876− format!("<link rel=\"canonical\" href=\"{}\">\n", html_escape(url))
877− } else {
878− format!("<link rel=\"canonical\" href=\"{}\">", html_escape(url))
879− }
880− }
881− None => String::new(),
882− };
883−
884− // Base URL
885− let base_html = match &doc.base_url {
886− Some(url) => {
887− if dev {
888− format!("<base href=\"{}\">\n", html_escape(url))
889− } else {
890− format!("<base href=\"{}\">", html_escape(url))
891− }
892− }
893− None => String::new(),
894− };
895−
896− // JSON-LD blocks
897− let json_ld_html: String = doc
898− .json_ld_blocks
899− .iter()
900− .map(|block| {
901− if dev {
902− format!(
903− "<script type=\"application/ld+json\">\n{}\n</script>\n",
904− block
905− )
906− } else {
907− format!("<script type=\"application/ld+json\">{}</script>", block)
908− }
909− })
910− .collect();
911−
912− // Manifest link
913− let manifest_html = if let Some(ref manifest) = doc.manifest {
914− let mut json = String::from("{");
915− json.push_str(&format!("\"name\":{},", json_str(&manifest.name)));
916− if let Some(ref short) = manifest.short_name {
917− json.push_str(&format!("\"short_name\":{},", json_str(short)));
918− }
919− json.push_str(&format!("\"start_url\":{},", json_str(&manifest.start_url)));
920− json.push_str(&format!("\"display\":{}", json_str(&manifest.display)));
921− if let Some(ref bg) = manifest.background_color {
922− json.push_str(&format!(",\"background_color\":{}", json_str(bg)));
923− }
924− if let Some(ref tc) = manifest.theme_color {
925− json.push_str(&format!(",\"theme_color\":{}", json_str(tc)));
926− }
927− if let Some(ref desc) = manifest.description {
928− json.push_str(&format!(",\"description\":{}", json_str(desc)));
929− }
930− if !manifest.icons.is_empty() {
931− json.push_str(",\"icons\":[");
932− for (i, (src, sizes)) in manifest.icons.iter().enumerate() {
933− if i > 0 {
934− json.push(',');
935− }
936− json.push_str(&format!(
937− "{{\"src\":{},\"sizes\":{},\"type\":\"image/png\"}}",
938− json_str(src),
939− json_str(sizes)
940− ));
941− }
942− json.push(']');
943− }
944− json.push('}');
945−
946− // Inline the manifest as a data URI
947− let encoded = base64_encode(json.as_bytes());
948− if dev {
949− format!(
950− "<link rel=\"manifest\" href=\"data:application/manifest+json;base64,{}\">\n",
951− encoded
952− )
953− } else {
954− format!(
955− "<link rel=\"manifest\" href=\"data:application/manifest+json;base64,{}\">",
956− encoded
957− )
958− }
959− } else {
960− String::new()
961− };
962−
963− // Preload hints (auto-detect fonts from @font-face)
964− let mut preload_html = String::new();
965− for (_, url) in &doc.font_faces {
966− if dev {
967− preload_html.push_str(&format!(
968− "<link rel=\"preload\" href=\"{}\" as=\"font\" type=\"font/woff2\" crossorigin>\n",
969− url
970− ));
971− } else {
972− preload_html.push_str(&format!(
973− "<link rel=\"preload\" href=\"{}\" as=\"font\" type=\"font/woff2\" crossorigin>",
974− url
975− ));
976− }
977− }
978− // Explicit preload hints from the document
979− for hint in &doc.preload_hints {
980− if dev {
981− preload_html.push_str(&format!(
982− "<link rel=\"preload\" href=\"{}\" as=\"{}\"{}>\n",
983− html_escape(&hint.href),
984− hint.as_type,
985− if hint.crossorigin { " crossorigin" } else { "" }
986− ));
987− } else {
988− preload_html.push_str(&format!(
989− "<link rel=\"preload\" href=\"{}\" as=\"{}\"{}>",
990− html_escape(&hint.href),
991− hint.as_type,
992− if hint.crossorigin { " crossorigin" } else { "" }
993− ));
994− }
995− }
996−
997− // Auto theme-color meta from @theme primary token
998− let theme_color_html = doc
999− .theme_tokens
1000− .iter()
1001− .find(|(name, _)| name == "primary" || name == "theme-color")
1002− .map(|(_, value)| {
1003− if dev {
1004− format!(
1005− "<meta name=\"theme-color\" content=\"{}\">\n",
1006− html_escape(value)
1007− )
1008− } else {
1009− format!(
1010− "<meta name=\"theme-color\" content=\"{}\">",
1011− html_escape(value)
1012− )
1013− }
1014− })
1015− .unwrap_or_default();
1016−
1017− // Focus-visible CSS for interactive elements (accessibility)
1018− let focus_visible_css = if ctx.has_interactive {
1019− if dev {
1020− "a:focus-visible, button:focus-visible, input:focus-visible, select:focus-visible, textarea:focus-visible { outline: 2px solid currentColor; outline-offset: 2px; }\n"
1021− } else {
1022− "a:focus-visible,button:focus-visible,input:focus-visible,select:focus-visible,textarea:focus-visible{outline:2px solid currentColor;outline-offset:2px}"
1023− }
1024− } else {
1025− ""
1026− };
1027−
1028− // Skip-to-content CSS (visually hidden but accessible)
1029− let skip_link_css = if has_main {
1030− if dev {
1031− ".hl-skip { position: absolute; left: -9999px; top: auto; width: 1px; height: 1px; overflow: hidden; z-index: 9999; padding: 8px 16px; background: #000; color: #fff; text-decoration: none; font-size: 14px; }\n.hl-skip:focus { left: 8px; top: 8px; width: auto; height: auto; overflow: visible; }\n"
1032− } else {
1033− ".hl-skip{position:absolute;left:-9999px;top:auto;width:1px;height:1px;overflow:hidden;z-index:9999;padding:8px 16px;background:#000;color:#fff;text-decoration:none;font-size:14px}.hl-skip:focus{left:8px;top:8px;width:auto;height:auto;overflow:visible}"
1034− }
1035− } else {
1036− ""
1037− };
1038−
1039− // Noscript fallback: show deferred content if JS is disabled
1040− let noscript_html = if ctx.has_defer {
1041− if dev {
1042− "<noscript><style>.hl-defer-placeholder { display: none; }</style></noscript>\n"
1043− } else {
1044− "<noscript><style>.hl-defer-placeholder{display:none}</style></noscript>"
1045− }
1046− } else {
1047− ""
1048− };
1049−
1050− let reset_css = reset_css(doc, dev, focus_visible_css, skip_link_css);
1051−
1052− match &doc.page_title {
1053− Some(title) => {
1054− if dev {
1055− format!(
1056− "\
1057−<!DOCTYPE html>
1058−<html{lang_attr}>
1059−<head>
1060−<meta charset=\"utf-8\">
1061−<meta name=\"viewport\" content=\"width=device-width, initial-scale=1\">
1062−<title>{title}</title>
1063−{theme_color_html}{base_html}{canonical_html}{manifest_html}{preload_html}{dns_prefetch_html}{meta_html}{og_html}{favicon_html}{json_ld_html}{head_html}\
1064−<style>
1065−{reset_css}{element_css}\
1066−</style>
1067−{noscript_html}\
1068−</head>
1069−<body>
1070−{body}\
1071−</body>
1072−</html>
1073−",
1074− title = html_escape(title),
1075− lang_attr = lang_attr,
1076− theme_color_html = theme_color_html,
1077− base_html = base_html,
1078− canonical_html = canonical_html,
1079− manifest_html = manifest_html,
1080− preload_html = preload_html,
1081− dns_prefetch_html = dns_prefetch_html,
1082− meta_html = meta_html,
1083− favicon_html = favicon_html,
1084− json_ld_html = json_ld_html,
1085− head_html = head_html,
1086− og_html = og_html,
1087− reset_css = reset_css,
1088− noscript_html = noscript_html,
1089− element_css = element_css,
1090− body = body,
1091− )
1092− } else {
1093− format!(
1094− "<!DOCTYPE html><html{lang_attr}><head><meta charset=\"utf-8\"><meta name=\"viewport\" content=\"width=device-width, initial-scale=1\"><title>{title}</title>{theme_color_html}{base_html}{canonical_html}{manifest_html}{preload_html}{dns_prefetch_html}{meta_html}{og_html}{favicon_html}{json_ld_html}{head_html}<style>{reset_css}{element_css}</style>{noscript_html}</head><body>{body}</body></html>",
1095− title = html_escape(title),
1096− lang_attr = lang_attr,
1097− theme_color_html = theme_color_html,
1098− base_html = base_html,
1099− canonical_html = canonical_html,
1100− manifest_html = manifest_html,
1101− preload_html = preload_html,
1102− dns_prefetch_html = dns_prefetch_html,
1103− meta_html = meta_html,
1104− og_html = og_html,
1105− favicon_html = favicon_html,
1106− json_ld_html = json_ld_html,
1107− head_html = head_html,
1108− reset_css = reset_css,
1109− noscript_html = noscript_html,
1110− element_css = element_css,
1111− body = body,
1112− )
1113− }
1114− }
1115− None => {
1116− if element_css.is_empty() {
1117− body
1118− } else if dev {
1119− format!("<style>\n{}</style>\n{}", element_css, body)
1120− } else {
1121− format!("<style>{}</style>{}", element_css, body)
1122− }
1123− }
1124− }
1125−}
1126−
1127−/// Encode `s` as a JSON string literal (with surrounding quotes).
1128−pub(crate) fn json_str(s: &str) -> String {
1129− let mut out = String::with_capacity(s.len() + 2);
1130− out.push('"');
1131− for c in s.chars() {
1132− match c {
1133− '"' => out.push_str("\\\""),
1134− '\\' => out.push_str("\\\\"),
1135− '\n' => out.push_str("\\n"),
1136− '\r' => out.push_str("\\r"),
1137− '\t' => out.push_str("\\t"),
1138− c if (c as u32) < 0x20 => out.push_str(&format!("\\u{:04x}", c as u32)),
1139− c => out.push(c),
1140− }
1141− }
1142− out.push('"');
1143− out
1144−}
948+ format!(
949+ "<!DOCTYPE html>{nl}<html{root_attrs}>{nl}<head>{nl}<meta charset=\"utf-8\">{nl}\
950+ {meta_html}<style>{nl}{reset_css}{element_css}</style>{nl}</head>{nl}\
951+ <body{body_attrs}>{nl}{body}</body>{nl}</html>{nl}",
952+ )
953+}
1145954
1146955/// Assemble every CSS block the document needs (font faces, custom
1147956/// properties, generated class rules, keyframes, and user CSS). Shared by
@@ -1149,61 +958,16 @@ pub(crate) fn json_str(s: &str) -> String {
1149958fn build_element_css(doc: &Document, styles: &StyleCollector, dev: bool) -> String {
1150959 let mut element_css = String::new();
1151960
1152− // @font-face rules, in declaration order
1153− for (name, url) in &doc.font_faces {
1154− let format_hint = if url.ends_with(".woff2") {
1155− " format('woff2')"
1156− } else if url.ends_with(".woff") {
1157− " format('woff')"
1158− } else if url.ends_with(".ttf") {
1159− " format('truetype')"
1160− } else if url.ends_with(".otf") {
1161− " format('opentype')"
1162− } else {
1163− ""
1164− };
1165− if dev {
1166− element_css.push_str(&format!(
1167− "@font-face {{\n font-family: '{}';\n src: url('{}'){};\n font-display: swap;\n}}\n",
1168− name, url, format_hint
1169− ));
1170− } else {
1171− element_css.push_str(&format!(
1172− "@font-face{{font-family:'{}';src:url('{}'){};font-display:swap}}",
1173− name, url, format_hint
1174− ));
1175− }
1176− }
1177−
1178− // Collect all CSS custom properties (explicit `@let --name` / `@theme`
1179− // tokens, plus any auto-extracted repeats) so they can be emitted in a
1180− // single `:root` block below.
961+ // Collect the CSS custom properties declared with `@let --name` so they
962+ // can be emitted in a single `:root` block below.
1181963 let mut root_vars: Vec<(String, String)> = Vec::new();
1182964 for (name, value) in &doc.css_vars {
1183965 root_vars.push((name.clone(), value.clone()));
1184966 }
1185− for (name, value) in &doc.theme_tokens {
1186− let css_name = format!("--{}", name);
1187− if !root_vars.iter().any(|(n, _)| *n == css_name) {
1188− root_vars.push((css_name, value.clone()));
1189− }
1190− }
1191967
1192− let styles_css = styles.to_css_formatted(dev, uses_layer(doc));
1193− // Fold literal values declared via `@theme` / `@let --name` back into
1194− // `var(--name)` references so the generated CSS actually uses the
1195− // custom properties emitted in `:root`.
1196− let styles_css = substitute_css_vars(&styles_css, &root_vars);
1197− // Further compress the CSS by auto-extracting any remaining literal
1198− // values that appear often enough for `var(--hN)` references to come out
1199− // shorter overall. Disabled in dev mode to keep the CSS readable.
1200− let styles_css = if dev {
1201− styles_css
1202− } else {
1203− let (new_css, auto_vars) = auto_extract_repeats(&styles_css, &root_vars);
1204− root_vars.extend(auto_vars);
1205− new_css
1206− };
968+ // Generated rules always go in htmlang's layers, so unlayered user CSS
969+ // (`@style`, `@raw`) overrides them regardless of specificity.
970+ let styles_css = styles.to_css_formatted(dev, &doc.scoped_css);
1207971
1208972 // Emit the :root block first so the cascade picks up the custom
1209973 // properties before the class rules consume them.
@@ -1228,93 +992,121 @@ fn build_element_css(doc: &Document, styles: &StyleCollector, dev: bool) -> Stri
1228992
1229993 element_css.push_str(&styles_css);
1230994
1231− // @keyframes
1232− for (name, kf_body) in &doc.keyframes {
1233− if dev {
1234− element_css.push_str(&format!("@keyframes {} {{\n{}\n}}\n", name, kf_body));
1235− } else {
1236− element_css.push_str(&format!("@keyframes {}{{{}}}", name, kf_body));
1237− }
1238− }
1239−
1240− // Auto-inject skeleton keyframe if skeleton attribute is used
1241− if element_css.contains("hl-skeleton") {
1242− if dev {
1243− element_css.push_str("@keyframes hl-skeleton {\n 0% { background-position: 200% 0; }\n 100% { background-position: -200% 0; }\n}\n");
1244− } else {
1245− element_css.push_str("@keyframes hl-skeleton{0%{background-position:200% 0}100%{background-position:-200% 0}}");
1246− }
1247− }
1248−
1249− let push_block = |css: &mut String, block: &str| {
995+ // @style blocks (custom CSS)
996+ for block in &doc.custom_css {
1250997 if dev {
1251− css.push_str(block);
1252− css.push('\n');
998+ element_css.push_str(block);
999+ element_css.push('\n');
12531000 } else {
1254− let minified: String = block.lines().map(|l| l.trim()).collect::<Vec<_>>().join("");
1255− css.push_str(&minified);
1256− }
1257− };
1258−
1259− // @style and @scope blocks (custom CSS)
1260− for block in doc.custom_css.iter().chain(&doc.scope_blocks) {
1261− push_block(&mut element_css, block);
1262− }
1263−
1264− // @starting-style blocks
1265− if !doc.starting_style_blocks.is_empty() {
1266− element_css.push_str(if dev { "@starting-style {\n" } else { "@starting-style{" });
1267− for block in &doc.starting_style_blocks {
1268− push_block(&mut element_css, block);
1001+ element_css.push_str(&compact_css(block));
12691002 }
1270− element_css.push_str(if dev { "}\n" } else { "}" });
12711003 }
12721004
12731005 element_css
12741006}
12751007
1276−/// Generated class rules go in `@layer htmlang` unless the page has custom
1277−/// `@style` CSS (which is unlayered and would then always win).
1278−fn uses_layer(doc: &Document) -> bool {
1279− doc.custom_css.is_empty()
1008+/// An `@style` body on one line: each line trimmed, and the lines joined with
1009+/// a space, so a value that goes on over two lines (`margin: 0` then `auto;`)
1010+/// keeps its words apart.
1011+fn compact_css(block: &str) -> String {
1012+ block
1013+ .lines()
1014+ .map(str::trim)
1015+ .filter(|l| !l.is_empty())
1016+ .collect::<Vec<_>>()
1017+ .join(" ")
12801018}
12811019
1282−/// Built-in reset rules. When generated rules are layered, the reset must be
1283−/// layered too (in an earlier layer): unlayered CSS beats every layer, so an
1284−/// unlayered `a{color:inherit}` would override `@link [color red]`.
1285−fn reset_css(doc: &Document, dev: bool, focus_visible_css: &str, skip_link_css: &str) -> String {
1286− let base = if dev {
1287− "*, *::before, *::after { box-sizing: border-box; }\nbody { margin: 0; font-family: system-ui, -apple-system, sans-serif; }\nimg { display: block; }\na { text-decoration: none; color: inherit; }\n"
1020+/// htmlang's own elements: those with a generated class, or the class of a
1021+/// function's scoped `@style`. The reset's rules for elements are kept to
1022+/// them, so `@raw` and `@markdown` content, and the page a fragment is put
1023+/// into, keep their own.
1024+const OWN_ELEMENTS: &str = ":where([class^=\"hl-\"],[class*=\" hl-\"])";
1025+
1026+/// htmlang's cascade layers, from the one that loses to the one that wins:
1027+/// the reset; the defaults of each element's kind (a heading's `margin:0`,
1028+/// a column's `display:flex`); the styles an element gets from an
1029+/// element prefix on an element around it (`@td:padding 8`) and from a
1030+/// function's scoped `@style`; and the element's own styles. So a
1031+/// scope's styles win over the defaults, and what an element says about
1032+/// itself wins over both. CSS outside any layer (`@style`, `@raw`) wins
1033+/// over all of them.
1034+const LAYERS: [&str; 4] = ["hl-reset", "hl-kind", "hl-inside", "htmlang"];
1035+
1036+/// Built-in reset rules, in a layer before `htmlang`: unlayered CSS beats
1037+/// every layer, so an unlayered rule here would override the generated
1038+/// ones. A page resets `box-sizing` everywhere and makes `<body>` a column
1039+/// that fills the window; a fragment, which goes into a page it doesn't
1040+/// own, touches only htmlang's own elements. In both, an element htmlang
1041+/// lays out stays hidden while it is `hidden`, a closed `<dialog>` or a
1042+/// popover that isn't showing: its generated `display` would otherwise
1043+/// beat the browser's `display: none`.
1044+fn reset_css(dev: bool, page: bool, focus_visible_css: &str) -> String {
1045+ let own = OWN_ELEMENTS;
1046+ let mut rules = Vec::new();
1047+ if page {
1048+ rules.push(if dev {
1049+ "*, *::before, *::after { box-sizing: border-box; }".to_string()
1050+ } else {
1051+ "*,*::before,*::after{box-sizing:border-box}".to_string()
1052+ });
1053+ rules.push(if dev {
1054+ "body { margin: 0; font-family: system-ui, -apple-system, sans-serif; display: flex; flex-direction: column; min-height: 100dvh; }".to_string()
1055+ } else {
1056+ "body{margin:0;font-family:system-ui,-apple-system,sans-serif;display:flex;flex-direction:column;min-height:100dvh}".to_string()
1057+ });
12881058 } else {
1289− "*,*::before,*::after{box-sizing:border-box}body{margin:0;font-family:system-ui,-apple-system,sans-serif}img{display:block}a{text-decoration:none;color:inherit}"
1290− };
1291− let rules = format!("{}{}{}", base, focus_visible_css, skip_link_css);
1292− if !uses_layer(doc) {
1293− rules
1294− } else if dev {
1295− format!("@layer hl-reset, htmlang;\n@layer hl-reset {{\n{}}}\n", rules)
1059+ rules.push(if dev {
1060+ format!("{own}, {own}::before, {own}::after {{ box-sizing: border-box; }}")
1061+ } else {
1062+ format!("{own},{own}::before,{own}::after{{box-sizing:border-box}}")
1063+ });
1064+ }
1065+ let hidden = "[hidden]:not([hidden=\"until-found\"]),dialog:not([open]):not(:popover-open),\
1066+ [popover]:not(:popover-open):not(dialog[open])";
1067+ rules.push(if dev {
1068+ format!("{own}:where({hidden}) {{ display: none !important; }}")
1069+ } else {
1070+ format!("{own}:where({hidden}){{display:none!important}}")
1071+ });
1072+ let mut rules = rules.join(if dev { "\n" } else { "" });
1073+ if dev {
1074+ rules.push('\n');
1075+ }
1076+ rules.push_str(focus_visible_css);
1077+ if dev {
1078+ format!(
1079+ "@layer {};\n@layer hl-reset {{\n{}}}\n",
1080+ LAYERS.join(", "),
1081+ rules
1082+ )
12961083 } else {
1297− format!("@layer hl-reset,htmlang;@layer hl-reset{{{}}}", rules)
1084+ format!("@layer {};@layer hl-reset{{{}}}", LAYERS.join(","), rules)
12981085 }
12991086}
13001087
13011088/// Generate an HTML fragment: body + optional <style>, no <html>/<head>/<body> wrapper.
1302−fn generate_partial_inner(doc: &Document, dev: bool) -> String {
1089+fn generate_partial_inner(doc: &Document, dev: bool, classes: &mut Vec<Class>) -> String {
13031090 let mut styles = StyleCollector::new();
13041091 let mut ctx = GenContext {
13051092 dev,
13061093 depth: 0,
1307− image_count: 0,
13081094 has_interactive: false,
1309− has_defer: false,
1095+ in_text: false,
1096+ flow: Flow::default(),
1097+ in_picture: false,
13101098 };
13111099 let mut body = String::new();
13121100
1313− for node in &doc.nodes {
1314− generate_node(node, None, &mut body, &mut styles, &mut ctx);
1315− }
1101+ generate_children(&doc.nodes, None, &mut body, &mut styles, &mut ctx);
13161102
1317− let element_css = build_element_css(doc, &styles, dev);
1103+ let mut element_css = build_element_css(doc, &styles, dev);
1104+ // htmlang's own elements get the reset's rules for elements (which
1105+ // also puts htmlang's layers in order)
1106+ if !styles.entries.is_empty() || !doc.scoped_css.is_empty() {
1107+ element_css.insert_str(0, &reset_css(dev, false, ""));
1108+ }
1109+ classes.extend(styles.classes());
13181110
13191111 if element_css.is_empty() {
13201112 body
@@ -1329,44 +1121,20 @@ fn generate_partial_inner(doc: &Document, dev: bool) -> String {
13291121// Node generation
13301122// ---------------------------------------------------------------------------
13311123
1124+/// Write `node`, which is inside an element with the layout `parent`
1125+/// (`None` at the top of the page).
13321126fn generate_node(
13331127 node: &Node,
1334− parent_kind: Option<&ElementKind>,
1128+ parent: Option<Layout>,
13351129 out: &mut String,
13361130 styles: &mut StyleCollector,
13371131 ctx: &mut GenContext,
13381132) {
13391133 match node {
1340− Node::Element(elem) => generate_element(elem, parent_kind, out, styles, ctx),
1134+ Node::Element(elem) => generate_element(elem, parent, out, styles, ctx),
13411135 Node::Text(segments) => {
1342− let needs_wrap = matches!(
1343− parent_kind,
1344− Some(ElementKind::Row)
1345− | Some(ElementKind::Column)
1346− | Some(ElementKind::El)
1347− | Some(ElementKind::Nav)
1348− | Some(ElementKind::Header)
1349− | Some(ElementKind::Footer)
1350− | Some(ElementKind::Main)
1351− | Some(ElementKind::Section)
1352− | Some(ElementKind::Article)
1353− | Some(ElementKind::Aside)
1354− | Some(ElementKind::ListItem)
1355− | Some(ElementKind::Form)
1356− | Some(ElementKind::Details)
1357− | Some(ElementKind::Figure)
1358− | Some(ElementKind::Blockquote)
1359− | Some(ElementKind::Dialog)
1360− | Some(ElementKind::DefinitionList)
1361− | Some(ElementKind::DefinitionDescription)
1362− | Some(ElementKind::Fieldset)
1363− | Some(ElementKind::Datalist)
1364− | Some(ElementKind::Grid)
1365− | Some(ElementKind::Stack)
1366− | Some(ElementKind::Noscript)
1367− | Some(ElementKind::Address)
1368− | Some(ElementKind::Search)
1369− );
1136+ // In a row, column or grid each line of text is a child
1137+ let needs_wrap = parent.is_some_and(Layout::is_container);
13701138 if needs_wrap {
13711139 out.push_str(&ctx.indent());
13721140 out.push_str("<span>");
@@ -1385,209 +1153,191 @@ fn generate_node(
13851153 }
13861154}
13871155
1388−/// HTML attributes that are passed through to the HTML tag rather than converted to CSS.
1389−const HTML_PASSTHROUGH_ATTRS: &[&str] = &[
1390− "type",
1391− "placeholder",
1392− "name",
1393− "value",
1394− "disabled",
1395− "required",
1396− "checked",
1397− "for",
1398− "action",
1399− "method",
1400− "autocomplete",
1401− "min",
1402− "max",
1403− "step",
1404− "pattern",
1405− "maxlength",
1406− "rows",
1407− "cols",
1408− "multiple",
1409− "alt",
1410− "role",
1411− "tabindex",
1412− "title",
1413− "autofocus",
1414− // Media
1415− "controls",
1416− "autoplay",
1417− "loop",
1418− "muted",
1419− "playsinline",
1420− "poster",
1421− "preload",
1422− // Image optimization
1423− "loading",
1424− "decoding",
1425− // Media src (explicit attribute form)
1426− "src",
1427− // New element attributes
1428− "datetime",
1429− "media",
1430− "sizes",
1431− "srcset",
1432− "list",
1433− // Details
1434− "open",
1435− // Form
1436− "novalidate",
1437− // Progress/Meter
1438− "low",
1439− "high",
1440− "optimum",
1441− // Table
1442− "colspan",
1443− "rowspan",
1444− "scope",
1445− // Popover API
1446− "popover",
1447− "popovertarget",
1448− "popovertargetaction",
1449− // Modern form/input hints
1450− "inputmode",
1451− "enterkeyhint",
1452− // Performance hints
1453− "fetchpriority",
1454− "blocking",
1455− // Global attrs
1456− "translate",
1457− "spellcheck",
1458− // ARIA live regions
1459− "aria-live",
1460− "aria-atomic",
1461− "aria-relevant",
1462−];
1156+/// What goes between two things written one after the other in an element
1157+/// with this layout (`None`: the top of the page): text flows, so its lines
1158+/// and children are joined with a space; in HTML's own layout, and at the
1159+/// top of the page, two lines of text are separated by a line break (a
1160+/// space, except where whitespace is kept, as in `@pre`).
1161+fn separator(layout: Option<Layout>, previous_is_text: bool, next: &Node) -> Option<char> {
1162+ match layout {
1163+ Some(Layout::Text) => Some(' '),
1164+ Some(Layout::Native) | None if previous_is_text && matches!(next, Node::Text(_)) => {
1165+ Some('\n')
1166+ }
1167+ _ => None,
1168+ }
1169+}
14631170
1464−/// Boolean HTML attributes (rendered without a value, e.g., `<input disabled>`).
1465−const BOOLEAN_HTML_ATTRS: &[&str] = &[
1466− "disabled",
1467− "required",
1468− "checked",
1469− "multiple",
1470− "controls",
1471− "autoplay",
1472− "loop",
1473− "muted",
1474− "playsinline",
1475− "open",
1476− "novalidate",
1477− "autofocus",
1478− "defer",
1479− "async",
1480− "nomodule",
1481− // Popover
1482− "popover",
1483−];
1171+/// Write the children of an element (or of a `@fragment`, which has no
1172+/// element of its own) laid out as `layout` (`None`: the top of the page).
1173+/// The first line of an element's text is its first child.
1174+fn generate_children(
1175+ children: &[Node],
1176+ layout: Option<Layout>,
1177+ out: &mut String,
1178+ styles: &mut StyleCollector,
1179+ ctx: &mut GenContext,
1180+) {
1181+ generate_run(children, layout, &mut None, out, styles, ctx);
1182+}
14841183
1485−fn emit_html_passthrough_attrs(out: &mut String, attrs: &[Attribute]) {
1486− for attr in attrs {
1487− let key = attr.key.as_str();
1488− let is_passthrough = HTML_PASSTHROUGH_ATTRS.contains(&key)
1489− || key.starts_with("aria-")
1490− || key.starts_with("data-");
1491− if !is_passthrough {
1184+/// [`generate_children`], with `previous` saying whether what was written
1185+/// last was a line of text (`None`: nothing yet). A `@fragment`'s children
1186+/// are written as if they stood in its place, so its lines are separated
1187+/// from the lines around it like any other lines.
1188+fn generate_run(
1189+ children: &[Node],
1190+ layout: Option<Layout>,
1191+ previous: &mut Option<bool>,
1192+ out: &mut String,
1193+ styles: &mut StyleCollector,
1194+ ctx: &mut GenContext,
1195+) {
1196+ for child in children {
1197+ if let Node::Element(elem) = child
1198+ && elem.kind == ElementKind::Fragment
1199+ {
1200+ generate_run(&elem.children, layout, previous, out, styles, ctx);
14921201 continue;
14931202 }
1494− if BOOLEAN_HTML_ATTRS.contains(&key) && attr.value.is_none() {
1495− out.push(' ');
1496− out.push_str(key);
1497− } else if let Some(val) = &attr.value {
1498− out.push(' ');
1499− out.push_str(key);
1500− out.push_str("=\"");
1501− out.push_str(&html_escape(strip_string_quotes(val)));
1502− out.push('"');
1203+ let start = out.len();
1204+ if let Some(previous_is_text) = *previous
1205+ && let Some(sep) = separator(layout, previous_is_text, child)
1206+ {
1207+ out.push(sep);
1208+ }
1209+ let body = out.len();
1210+ generate_node(child, layout, out, styles, ctx);
1211+ // A child that writes nothing (an empty `@fragment`) takes no
1212+ // separator either, so text never gets two spaces in a row
1213+ if out.len() == body {
1214+ out.truncate(start);
1215+ continue;
15031216 }
1217+ *previous = Some(matches!(child, Node::Text(_)));
15041218 }
15051219}
15061220
1507−/// If the value is wrapped in a single pair of matching quotes (e.g.
1508−/// `"Avatar"`), return the inner content. Quotes act as source-level
1509−/// delimiters in the `.hl` syntax and shouldn't leak into HTML attribute
1510−/// values. Multi-quoted values like `"h h" "s m"` are left unchanged —
1511−/// those are real string tokens (used e.g. by CSS `grid-template-areas`).
1512−fn strip_string_quotes(val: &str) -> &str {
1513− let bytes = val.as_bytes();
1514− if bytes.len() < 2 {
1515− return val;
1516− }
1517− let first = bytes[0];
1518− let last = bytes[bytes.len() - 1];
1519− if (first == b'"' && last == b'"') || (first == b'\'' && last == b'\'') {
1520− let inner = &val[1..val.len() - 1];
1521− if !inner.as_bytes().contains(&first) {
1522− return inner;
1221+/// Emit the element's leading argument as its attribute (`@iframe URL` →
1222+/// `src="URL"`, `@form /submit` → `action="/submit"`, `@link /a` →
1223+/// `href="/a"`), first, before the class. `@image [inline] photo.png` puts
1224+/// the file itself into the page.
1225+fn emit_argument_attr(out: &mut String, elem: &Element, in_picture: bool) {
1226+ let (Some(attr), Some(value)) = (elem.kind.leading_attribute(in_picture), &elem.argument)
1227+ else {
1228+ return;
1229+ };
1230+ // `@image [inline]`'s file is already a `data:` URI (see the parser)
1231+ let value = html_escape(value);
1232+ out.push(' ');
1233+ out.push_str(attr);
1234+ out.push_str("=\"");
1235+ out.push_str(&value);
1236+ out.push('"');
1237+}
1238+
1239+/// A file's bytes as a `data:` URI, its type from its extension.
1240+pub(crate) fn data_uri(path: &str, data: &[u8]) -> String {
1241+ let mime = match path
1242+ .rsplit('.')
1243+ .next()
1244+ .map(str::to_ascii_lowercase)
1245+ .as_deref()
1246+ {
1247+ Some("png") => "image/png",
1248+ Some("jpg" | "jpeg") => "image/jpeg",
1249+ Some("gif") => "image/gif",
1250+ Some("webp") => "image/webp",
1251+ Some("avif") => "image/avif",
1252+ Some("svg") => "image/svg+xml",
1253+ Some("ico") => "image/x-icon",
1254+ _ => "application/octet-stream",
1255+ };
1256+ format!("data:{};base64,{}", mime, base64_encode(data))
1257+}
1258+
1259+/// Emit HTML attributes: `key=value` ones (except `id` / `class`, which
1260+/// are emitted with the generated class) and flags like `required`.
1261+fn emit_html_attrs(out: &mut String, attrs: &[Attribute]) {
1262+ for attr in html_attrs(attrs) {
1263+ let key = attr.key.as_str();
1264+ if key != "id" && key != "class" {
1265+ push_html_attr(out, attr);
15231266 }
15241267 }
1525− val
1268+}
1269+
1270+/// The HTML attributes of `attrs`, `key=value` ones and flags, each name
1271+/// once: the later one wins, as a style does. (Of two attributes with one
1272+/// name, the browser keeps the first, so a bundle's attribute or a
1273+/// function's own would win over one written after it.)
1274+fn html_attrs(attrs: &[Attribute]) -> impl Iterator<Item = &Attribute> {
1275+ let is_html =
1276+ |a: &Attribute| a.html || (a.value.is_none() && crate::vocab::is_html_flag(&a.key));
1277+ attrs.iter().enumerate().filter_map(move |(i, attr)| {
1278+ let later = attrs[i + 1..]
1279+ .iter()
1280+ .any(|other| is_html(other) && other.key == attr.key);
1281+ (is_html(attr) && !later).then_some(attr)
1282+ })
1283+}
1284+
1285+/// ` key="value"`, or ` key` for a flag.
1286+fn push_html_attr(out: &mut String, attr: &Attribute) {
1287+ out.push(' ');
1288+ out.push_str(&attr.key);
1289+ if attr.html {
1290+ out.push_str("=\"");
1291+ // Quoted text has already lost its quotes (see parser.rs)
1292+ out.push_str(&html_escape(attr.value.as_deref().unwrap_or("")));
1293+ out.push('"');
1294+ }
15261295}
15271296
15281297// True if any direct child is `@in-front` or `@behind`. Such children render
15291298// as absolutely positioned overlays, so the parent automatically becomes a
15301299// positioning context (position:relative + isolation:isolate).
15311300fn has_overlay_children(elem: &Element) -> bool {
1532− elem.children.iter().any(|child| {
1301+ holds_overlays(&elem.children)
1302+}
1303+
1304+fn holds_overlays(children: &[Node]) -> bool {
1305+ children.iter().any(|child| {
15331306 matches!(
15341307 child,
1535− Node::Element(e) if matches!(e.kind, ElementKind::InFront | ElementKind::Behind)
1308+ Node::Element(e) if e.kind.is_tag("in-front") || e.kind.is_tag("behind")
15361309 )
15371310 })
15381311}
15391312
15401313fn generate_element(
15411314 elem: &Element,
1542− parent_kind: Option<&ElementKind>,
1315+ parent: Option<Layout>,
15431316 out: &mut String,
15441317 styles: &mut StyleCollector,
15451318 ctx: &mut GenContext,
15461319) {
15471320 // Self-closing elements
1548− if matches!(
1549− elem.kind,
1550− ElementKind::Image
1551− | ElementKind::Input
1552− | ElementKind::HorizontalRule
1553− | ElementKind::Source
1554− | ElementKind::Spacer
1555− ) {
1556− generate_self_closing(elem, parent_kind, out, styles, ctx);
1321+ if elem.kind.layout() == Layout::Void {
1322+ generate_self_closing(elem, parent, out, styles, ctx);
15571323 return;
15581324 }
1559− // @script renders as <script> with raw body content (no HTML escaping)
1560− if elem.kind == ElementKind::Script {
1325+ // A verbatim element (@script) writes its body as it is, with no HTML
1326+ // escaping; it isn't shown, so it has no class (its styles are an error)
1327+ if elem.kind.is_verbatim() {
1328+ let tag = elem.kind.spec().map_or("script", |spec| spec.html);
15611329 out.push_str(&ctx.indent());
1562− out.push_str("<script");
1563− // Pass through src, type, defer, async, etc.
1564− for attr in &elem.attrs {
1565− let key = attr.key.as_str();
1566− if matches!(
1567− key,
1568− "src"
1569− | "type"
1570− | "defer"
1571− | "async"
1572− | "crossorigin"
1573− | "integrity"
1574− | "nomodule"
1575− | "id"
1576− ) {
1577− if let Some(val) = &attr.value {
1578− out.push(' ');
1579− out.push_str(key);
1580− out.push_str("=\"");
1581− out.push_str(&html_escape(val));
1582− out.push('"');
1583− } else {
1584− out.push(' ');
1585− out.push_str(key);
1586− }
1330+ out.push('<');
1331+ out.push_str(tag);
1332+ emit_argument_attr(out, elem, false);
1333+ let (id, class) = extract_id_class(&elem.attrs);
1334+ for (key, value) in [("id", id), ("class", class)] {
1335+ if let Some(value) = value {
1336+ out.push_str(&format!(" {}=\"{}\"", key, html_escape(&value)));
15871337 }
15881338 }
1339+ emit_html_attrs(out, &elem.attrs);
15891340 out.push('>');
1590− // Children are raw JS code, not HTML
15911341 for child in &elem.children {
15921342 match child {
15931343 Node::Text(segments) => {
@@ -1601,46 +1351,10 @@ fn generate_element(
16011351 _ => {}
16021352 }
16031353 }
1604− out.push_str("</script>");
1605− out.push_str(ctx.nl());
1606− return;
1607− }
1608− // @breadcrumb generates semantic <nav aria-label="breadcrumb"><ol>...</ol></nav>
1609− if elem.kind == ElementKind::Breadcrumb {
1610− let gen_class = compute_class(&elem.attrs, &elem.kind, parent_kind, styles, false);
1611− let (id, user_class) = extract_id_class(&elem.attrs);
1612− out.push_str(&ctx.indent());
1613− out.push_str("<nav aria-label=\"breadcrumb\"");
1614− emit_class_attr(out, gen_class.as_deref(), user_class.as_deref());
1615− if let Some(id) = id {
1616− out.push_str(" id=\"");
1617− out.push_str(&html_escape(&id));
1618− out.push('"');
1619− }
1354+ out.push_str("</");
1355+ out.push_str(tag);
16201356 out.push('>');
16211357 out.push_str(ctx.nl());
1622− ctx.depth += 1;
1623− out.push_str(&ctx.indent());
1624− out.push_str("<ol>");
1625− out.push_str(ctx.nl());
1626− ctx.depth += 1;
1627− for child in &elem.children {
1628− out.push_str(&ctx.indent());
1629− out.push_str("<li>");
1630− let mut buf = String::new();
1631− generate_node(child, Some(&elem.kind), &mut buf, styles, ctx);
1632− out.push_str(buf.trim());
1633− out.push_str("</li>");
1634− out.push_str(ctx.nl());
1635− }
1636− ctx.depth -= 1;
1637− out.push_str(&ctx.indent());
1638− out.push_str("</ol>");
1639− out.push_str(ctx.nl());
1640− ctx.depth -= 1;
1641− out.push_str(&ctx.indent());
1642− out.push_str("</nav>");
1643− out.push_str(ctx.nl());
16441358 return;
16451359 }
16461360 if elem.kind == ElementKind::Children {
@@ -1650,209 +1364,38 @@ fn generate_element(
16501364 return;
16511365 }
16521366 if elem.kind == ElementKind::Fragment {
1653− // Render children without a wrapper element
1654− for child in &elem.children {
1655− generate_node(child, parent_kind, out, styles, ctx);
1656− }
1367+ // Render children without a wrapper element, as if they were
1368+ // written where the fragment is
1369+ generate_children(&elem.children, parent, out, styles, ctx);
16571370 return;
16581371 }
16591372
1373+ let mut own = Flow::of(elem);
16601374 let tag = match &elem.kind {
1661− ElementKind::Row
1662− | ElementKind::Column
1663− | ElementKind::El
1664− | ElementKind::Grid
1665− | ElementKind::Stack
1666− | ElementKind::InFront
1667− | ElementKind::Behind => "div",
1375+ ElementKind::Row | ElementKind::El => "div",
16681376 ElementKind::Text => "span",
16691377 ElementKind::Paragraph => "p",
16701378 ElementKind::Link => "a",
1671− ElementKind::Button => "button",
1672− ElementKind::Select => "select",
1673− ElementKind::Textarea => "textarea",
1674− ElementKind::Option => "option",
1675− ElementKind::Label => "label",
1676− // Semantic elements
1677− ElementKind::Nav => "nav",
1678− ElementKind::Header => "header",
1679− ElementKind::Footer => "footer",
1680− ElementKind::Main => "main",
1681− ElementKind::Section => "section",
1682− ElementKind::Article => "article",
1683− ElementKind::Aside => "aside",
1684− // List
1685− ElementKind::List => {
1686− if elem.attrs.iter().any(|a| a.key == "ordered") {
1687− "ol"
1688− } else {
1689− "ul"
1690− }
1691− }
1692− ElementKind::ListItem => "li",
1693− // Table
1694− ElementKind::Table => "table",
1695− ElementKind::TableHead => "thead",
1696− ElementKind::TableBody => "tbody",
1697− ElementKind::TableRow => "tr",
1698− ElementKind::TableCell => "td",
1699− ElementKind::TableHeaderCell => "th",
1700− // Media
1701− ElementKind::Video => "video",
1702− ElementKind::Audio => "audio",
1703− // Additional semantic elements
1704− ElementKind::Form => "form",
1705− ElementKind::Details => "details",
1706− ElementKind::Summary => "summary",
1707− ElementKind::Blockquote => "blockquote",
1708− ElementKind::Cite => "cite",
1709− ElementKind::Code => "code",
1710− ElementKind::Pre => "pre",
1711− ElementKind::Figure => "figure",
1712− ElementKind::FigCaption => "figcaption",
1713− ElementKind::Progress => "progress",
1714− ElementKind::Meter => "meter",
1715− // New elements
1716− ElementKind::Dialog => "dialog",
1717− ElementKind::DefinitionList => "dl",
1718− ElementKind::DefinitionTerm => "dt",
1719− ElementKind::DefinitionDescription => "dd",
1720− ElementKind::Fieldset => "fieldset",
1721− ElementKind::Legend => "legend",
1722− ElementKind::Picture => "picture",
1723− ElementKind::Time => "time",
1724− ElementKind::Mark => "mark",
1725− ElementKind::Kbd => "kbd",
1726− ElementKind::Abbr => "abbr",
1727− ElementKind::Datalist => "datalist",
1728− ElementKind::Iframe => "iframe",
1729− ElementKind::Output => "output",
1730− ElementKind::Canvas => "canvas",
1731− ElementKind::Badge => "span",
1732− ElementKind::Tooltip => "span",
1733− ElementKind::Avatar => "div",
1734− ElementKind::Carousel => "div",
1735− ElementKind::Chip => "span",
1736− ElementKind::Tag => "span",
1737− ElementKind::Noscript => "noscript",
1738− ElementKind::Address => "address",
1739− ElementKind::Search => "search",
1740− // Heading elements
1741− ElementKind::H1 => "h1",
1742− ElementKind::H2 => "h2",
1743− ElementKind::H3 => "h3",
1744− ElementKind::H4 => "h4",
1745− ElementKind::H5 => "h5",
1746− ElementKind::H6 => "h6",
1747− ElementKind::Image
1748− | ElementKind::Input
1749− | ElementKind::HorizontalRule
1750− | ElementKind::Children
1751− | ElementKind::Slot(_)
1752− | ElementKind::Fragment
1753− | ElementKind::Source
1754− | ElementKind::Spacer
1755− | ElementKind::Script
1756− | ElementKind::Breadcrumb => unreachable!(),
1757− };
1758−
1759− let kind_label = match elem.kind {
1760− ElementKind::Row => "row",
1761− ElementKind::Column => "column",
1762− ElementKind::El => "el",
1763− ElementKind::Text => "text",
1764− ElementKind::Paragraph => "paragraph",
1765− ElementKind::Link => "link",
1766− ElementKind::Button => "button",
1767− ElementKind::Select => "select",
1768− ElementKind::Textarea => "textarea",
1769− ElementKind::Option => "option",
1770− ElementKind::Label => "label",
1771− ElementKind::Nav => "nav",
1772− ElementKind::Header => "header",
1773− ElementKind::Footer => "footer",
1774− ElementKind::Main => "main",
1775− ElementKind::Section => "section",
1776− ElementKind::Article => "article",
1777− ElementKind::Aside => "aside",
1778− ElementKind::List => "list",
1779− ElementKind::ListItem => "item",
1780− ElementKind::Table => "table",
1781− ElementKind::TableHead => "thead",
1782− ElementKind::TableBody => "tbody",
1783− ElementKind::TableRow => "tr",
1784− ElementKind::TableCell => "td",
1785− ElementKind::TableHeaderCell => "th",
1786− ElementKind::Video => "video",
1787− ElementKind::Audio => "audio",
1788− ElementKind::Form => "form",
1789− ElementKind::Details => "details",
1790− ElementKind::Summary => "summary",
1791− ElementKind::Blockquote => "blockquote",
1792− ElementKind::Cite => "cite",
1793− ElementKind::Code => "code",
1794− ElementKind::Pre => "pre",
1795− ElementKind::Figure => "figure",
1796− ElementKind::FigCaption => "figcaption",
1797− ElementKind::Fragment => "fragment",
1798− ElementKind::Dialog => "dialog",
1799− ElementKind::DefinitionList => "dl",
1800− ElementKind::DefinitionTerm => "dt",
1801− ElementKind::DefinitionDescription => "dd",
1802− ElementKind::Fieldset => "fieldset",
1803− ElementKind::Legend => "legend",
1804− ElementKind::Picture => "picture",
1805− ElementKind::Time => "time",
1806− ElementKind::Mark => "mark",
1807− ElementKind::Kbd => "kbd",
1808− ElementKind::Abbr => "abbr",
1809− ElementKind::Datalist => "datalist",
1810− ElementKind::Iframe => "iframe",
1811− ElementKind::Output => "output",
1812− ElementKind::Canvas => "canvas",
1813− ElementKind::Grid => "grid",
1814− ElementKind::Stack => "stack",
1815− ElementKind::Badge => "badge",
1816− ElementKind::Tooltip => "tooltip",
1817− ElementKind::Avatar => "avatar",
1818− ElementKind::Carousel => "carousel",
1819− ElementKind::Chip => "chip",
1820− ElementKind::Tag => "tag",
1821− ElementKind::Noscript => "noscript",
1822− ElementKind::Address => "address",
1823− ElementKind::Search => "search",
1824− ElementKind::InFront => "in-front",
1825− ElementKind::Behind => "behind",
1826− ElementKind::H1 => "h1",
1827− ElementKind::H2 => "h2",
1828− ElementKind::H3 => "h3",
1829− ElementKind::H4 => "h4",
1830− ElementKind::H5 => "h5",
1831− ElementKind::H6 => "h6",
1379+ ElementKind::Tag(spec) => spec.html,
18321380 _ => "",
18331381 };
1382+ // Inside text, htmlang's own `<div>` is a `<span>`, which text can
1383+ // hold (directly in text, a row, column or grid is also laid out
1384+ // inline: see `Site::inline`)
1385+ let in_text = ctx.in_text || parent == Some(Layout::Text);
1386+ let tag = if in_text && tag == "div" { "span" } else { tag };
1387+ let kind_label = elem.kind.name();
18341388
18351389 // Track interactive elements for focus-visible CSS
1836− if matches!(
1837− elem.kind,
1838− ElementKind::Link
1839− | ElementKind::Button
1840− | ElementKind::Input
1841− | ElementKind::Select
1842− | ElementKind::Textarea
1843− ) {
1390+ if elem.kind == ElementKind::Link
1391+ || matches!(kind_label, "button" | "input" | "select" | "textarea")
1392+ {
18441393 ctx.has_interactive = true;
18451394 }
18461395
18471396 // Compute CSS for each state and get a class name
1848− let overlay_children = has_overlay_children(elem);
1849− let gen_class = compute_class(
1850− &elem.attrs,
1851− &elem.kind,
1852− parent_kind,
1853− styles,
1854− overlay_children,
1855− );
1397+ let gen_class = element_class(elem, &Site::new(elem, parent, &ctx.flow), styles);
1398+ own.class = gen_class.clone();
18561399 let (id, user_class) = extract_id_class(&elem.attrs);
18571400
18581401 if ctx.dev && elem.line_num > 0 {
@@ -1866,85 +1409,9 @@ fn generate_element(
18661409 out.push('<');
18671410 out.push_str(tag);
18681411
1869− // @main gets id="hl-main" for skip-to-content link (unless user set an id)
1870− if elem.kind == ElementKind::Main && id.is_none() {
1871− out.push_str(" id=\"hl-main\"");
1872− }
1873−
1874− if elem.kind == ElementKind::Link
1875− && let Some(url) = &elem.argument
1876− {
1877− out.push_str(" href=\"");
1878− out.push_str(&html_escape(url));
1879− out.push('"');
1880− // Auto rel="noopener noreferrer" and target="_blank" for external links
1881− let is_external = url.starts_with("http://") || url.starts_with("https://");
1882− if is_external {
1883− let has_rel = elem.attrs.iter().any(|a| a.key == "rel");
1884− let has_target = elem.attrs.iter().any(|a| a.key == "target");
1885− if !has_rel {
1886− out.push_str(" rel=\"noopener noreferrer\"");
1887− }
1888− if !has_target {
1889− out.push_str(" target=\"_blank\"");
1890− }
1891− }
1892− }
1893−
1894− // Video/Audio src
1895− if matches!(elem.kind, ElementKind::Video | ElementKind::Audio)
1896− && let Some(src) = &elem.argument
1897− {
1898− out.push_str(" src=\"");
1899− out.push_str(&html_escape(src));
1900− out.push('"');
1901− }
1902−
1903− // Form action
1904− if elem.kind == ElementKind::Form
1905− && let Some(action) = &elem.argument
1906− {
1907− out.push_str(" action=\"");
1908− out.push_str(&html_escape(action));
1909− out.push('"');
1910− }
1911−
1912− // Iframe src
1913− if elem.kind == ElementKind::Iframe
1914− && let Some(src) = &elem.argument
1915− {
1916− out.push_str(" src=\"");
1917− out.push_str(&html_escape(src));
1918− out.push('"');
1919− }
1920−
1921− // Tooltip title
1922− if elem.kind == ElementKind::Tooltip
1923− && let Some(text) = &elem.argument
1924− {
1925− out.push_str(" title=\"");
1926− out.push_str(&html_escape(text));
1927− out.push('"');
1928− }
1412+ emit_argument_attr(out, elem, ctx.in_picture);
19291413
1930− // Critical CSS: inline styles directly instead of using a class
1931− let is_critical = elem.attrs.iter().any(|a| a.key == "critical");
1932− if is_critical {
1933− let inline_css = attrs_to_css(&elem.attrs, "", &elem.kind, parent_kind, overlay_children);
1934− if !inline_css.is_empty() {
1935− out.push_str(" style=\"");
1936− out.push_str(&html_escape(&inline_css));
1937− out.push('"');
1938− }
1939− // Still use class for non-base styles (pseudo, responsive, etc.)
1940− if gen_class.as_deref().is_some_and(|c| !c.is_empty()) {
1941− emit_class_attr(out, gen_class.as_deref(), user_class.as_deref());
1942− } else if let Some(ref uc) = user_class {
1943− emit_class_attr(out, None, Some(uc));
1944− }
1945− } else {
1946− emit_class_attr(out, gen_class.as_deref(), user_class.as_deref());
1947− }
1414+ emit_class_attr(out, gen_class.as_deref(), user_class.as_deref());
19481415
19491416 if let Some(id) = id {
19501417 out.push_str(" id=\"");
@@ -1952,7 +1419,7 @@ fn generate_element(
19521419 out.push('"');
19531420 }
19541421
1955− emit_html_passthrough_attrs(out, &elem.attrs);
1422+ emit_html_attrs(out, &elem.attrs);
19561423
19571424 // Source map attributes in dev mode
19581425 if ctx.dev && elem.line_num > 0 {
@@ -1963,66 +1430,27 @@ fn generate_element(
19631430 }
19641431
19651432 out.push('>');
1433+ // In `<pre>` and `<textarea>` every space and line break shows, so
1434+ // readable (dev) output adds none there: a code sample's lines stay
1435+ // exactly as written
1436+ let outer_dev = ctx.dev;
1437+ ctx.dev &= !matches!(tag, "pre" | "textarea");
19661438 out.push_str(ctx.nl());
19671439
1968− // Inline text argument
1969− if matches!(
1970− elem.kind,
1971− ElementKind::Text
1972− | ElementKind::Button
1973− | ElementKind::Label
1974− | ElementKind::Option
1975− | ElementKind::Textarea
1976− | ElementKind::ListItem
1977− | ElementKind::TableCell
1978− | ElementKind::TableHeaderCell
1979− | ElementKind::Summary
1980− | ElementKind::Cite
1981− | ElementKind::Code
1982− | ElementKind::FigCaption
1983− | ElementKind::Legend
1984− | ElementKind::DefinitionTerm
1985− | ElementKind::Mark
1986− | ElementKind::Kbd
1987− | ElementKind::Abbr
1988− | ElementKind::Time
1989− | ElementKind::DefinitionDescription
1990− | ElementKind::Badge
1991− | ElementKind::Tooltip
1992− | ElementKind::Chip
1993− | ElementKind::Tag
1994− | ElementKind::H1
1995− | ElementKind::H2
1996− | ElementKind::H3
1997− | ElementKind::H4
1998− | ElementKind::H5
1999− | ElementKind::H6
2000− ) && let Some(text) = &elem.argument
2001− {
2002− out.push_str(&html_escape(text));
2003− }
2004−
2005− // Children
1440+ let layout = elem.kind.layout();
20061441 ctx.depth += 1;
2007− let is_paragraph = matches!(
2008− elem.kind,
2009− ElementKind::Paragraph
2010− | ElementKind::H1
2011− | ElementKind::H2
2012− | ElementKind::H3
2013− | ElementKind::H4
2014− | ElementKind::H5
2015− | ElementKind::H6
2016− );
2017− for (i, child) in elem.children.iter().enumerate() {
2018− generate_node(child, Some(&elem.kind), out, styles, ctx);
2019− if is_paragraph && i < elem.children.len() - 1 {
2020− out.push(' ');
2021− }
2022− }
1442+ let outer_in_text = ctx.in_text;
1443+ ctx.in_text = in_text || layout == Layout::Text;
1444+ let outer_flow = std::mem::replace(&mut ctx.flow, own);
1445+ let outer_picture = std::mem::replace(&mut ctx.in_picture, elem.kind.is_tag("picture"));
1446+ generate_children(&elem.children, Some(layout), out, styles, ctx);
1447+ ctx.in_picture = outer_picture;
1448+ ctx.flow = outer_flow;
1449+ ctx.in_text = outer_in_text;
20231450 ctx.depth -= 1;
20241451
20251452 out.push_str(&ctx.indent());
1453+ ctx.dev = outer_dev;
20261454 out.push_str("</");
20271455 out.push_str(tag);
20281456 out.push('>');
@@ -2031,21 +1459,18 @@ fn generate_element(
20311459
20321460fn generate_self_closing(
20331461 elem: &Element,
2034− parent_kind: Option<&ElementKind>,
1462+ parent: Option<Layout>,
20351463 out: &mut String,
20361464 styles: &mut StyleCollector,
20371465 ctx: &mut GenContext,
20381466) {
2039− let gen_class = compute_class(&elem.attrs, &elem.kind, parent_kind, styles, false);
1467+ let gen_class = element_class(elem, &Site::new(elem, parent, &ctx.flow), styles);
20401468 let (id, user_class) = extract_id_class(&elem.attrs);
20411469
2042− let (tag, kind_label) = match elem.kind {
1470+ let (tag, kind_label) = match &elem.kind {
20431471 ElementKind::Image => ("img", "image"),
2044− ElementKind::Input => ("input", "input"),
2045− ElementKind::HorizontalRule => ("hr", "hr"),
2046− ElementKind::Source => ("source", "source"),
2047− ElementKind::Spacer => ("div", "spacer"),
2048− _ => unreachable!(),
1472+ ElementKind::Tag(spec) => (spec.html, spec.name),
1473+ _ => unreachable!("not a void element: {:?}", elem.kind),
20491474 };
20501475
20511476 if ctx.dev && elem.line_num > 0 {
@@ -2058,43 +1483,7 @@ fn generate_self_closing(
20581483 out.push_str(&ctx.indent());
20591484 out.push('<');
20601485 out.push_str(tag);
2061−
2062− // Image src (with optional non-SVG base64 inlining)
2063− if elem.kind == ElementKind::Image {
2064− let src = elem.argument.as_deref().unwrap_or("");
2065− let is_inline = elem.attrs.iter().any(|a| a.key == "inline");
2066− if is_inline && !src.is_empty() && !src.ends_with(".svg") {
2067− let mime = if src.ends_with(".png") {
2068− "image/png"
2069− } else if src.ends_with(".jpg") || src.ends_with(".jpeg") {
2070− "image/jpeg"
2071− } else if src.ends_with(".gif") {
2072− "image/gif"
2073− } else if src.ends_with(".webp") {
2074− "image/webp"
2075− } else if src.ends_with(".avif") {
2076− "image/avif"
2077− } else {
2078− "application/octet-stream"
2079− };
2080− if let Ok(data) = std::fs::read(src) {
2081− let b64 = base64_encode(&data);
2082− out.push_str(" src=\"data:");
2083− out.push_str(mime);
2084− out.push_str(";base64,");
2085− out.push_str(&b64);
2086− out.push('"');
2087− } else {
2088− out.push_str(" src=\"");
2089− out.push_str(&html_escape(src));
2090− out.push('"');
2091− }
2092− } else {
2093− out.push_str(" src=\"");
2094− out.push_str(&html_escape(src));
2095− out.push('"');
2096− }
2097− }
1486+ emit_argument_attr(out, elem, ctx.in_picture);
20981487
20991488 emit_class_attr(out, gen_class.as_deref(), user_class.as_deref());
21001489
@@ -2104,7 +1493,7 @@ fn generate_self_closing(
21041493 out.push('"');
21051494 }
21061495
2107− emit_html_passthrough_attrs(out, &elem.attrs);
1496+ emit_html_attrs(out, &elem.attrs);
21081497
21091498 // Source map attributes in dev mode (self-closing)
21101499 if ctx.dev && elem.line_num > 0 {
@@ -2114,93 +1503,6 @@ fn generate_self_closing(
21141503 ));
21151504 }
21161505
2117− // Image optimization: auto-add loading="lazy" and decoding="async"
2118− if elem.kind == ElementKind::Image {
2119− // SVG inlining: @image [inline] logo.svg
2120− if elem.attrs.iter().any(|a| a.key == "inline")
2121− && let Some(src) = &elem.argument
2122− && src.ends_with(".svg")
2123− && let Ok(svg_content) = std::fs::read_to_string(src)
2124− {
2125− // Close the tag we opened, then emit inline SVG instead
2126− out.truncate(out.rfind('<').unwrap_or(0));
2127− out.push_str(&ctx.indent());
2128− out.push_str(svg_content.trim());
2129− out.push_str(ctx.nl());
2130− return;
2131− }
2132− // Responsive srcset: @image photo.jpg [responsive 400 800 1200]
2133− let responsive_attr = elem.attrs.iter().find(|a| a.key == "responsive");
2134− if let Some(resp) = responsive_attr
2135− && let Some(ref sizes_str) = resp.value
2136− {
2137− let widths: Vec<&str> = sizes_str.split_whitespace().collect();
2138− if !widths.is_empty() {
2139− let src = elem.argument.as_deref().unwrap_or("");
2140− if !src.is_empty() {
2141− // Generate srcset with width descriptors
2142− // Convention: file-{width}.ext (e.g., photo-400.jpg)
2143− let dot_pos = src.rfind('.').unwrap_or(src.len());
2144− let base = &src[..dot_pos];
2145− let ext = &src[dot_pos..];
2146− let mut srcset_parts = Vec::new();
2147− for w in &widths {
2148− srcset_parts.push(format!("{}-{}{} {}w", base, w, ext, w));
2149− }
2150− out.push_str(" srcset=\"");
2151− out.push_str(&srcset_parts.join(", "));
2152− out.push('"');
2153− // Generate sizes attribute
2154− let max_width = widths.last().unwrap_or(&"100vw");
2155− out.push_str(&format!(
2156− " sizes=\"(max-width: {}px) 100vw, {}px\"",
2157− max_width, max_width
2158− ));
2159− }
2160− }
2161− }
2162−
2163− // Auto image dimensions: read local image file to inject width/height + aspect-ratio
2164− let has_width = elem.attrs.iter().any(|a| a.key == "width");
2165− let has_height = elem.attrs.iter().any(|a| a.key == "height");
2166− if (!has_width || !has_height)
2167− && let Some(ref src) = elem.argument
2168− && !src.starts_with("http://")
2169− && !src.starts_with("https://")
2170− && !src.starts_with("data:")
2171− && let Some((w, h)) = read_image_dimensions(src)
2172− {
2173− // Intrinsic size attributes only when neither dimension is set in
2174− // CSS; with one CSS dimension, a leftover intrinsic attribute for
2175− // the other would distort the image (200 wide but 1000 tall).
2176− if !has_width && !has_height {
2177− out.push_str(&format!(" width=\"{}\" height=\"{}\"", w, h));
2178− }
2179− // Auto aspect-ratio to prevent CLS
2180− if !elem.attrs.iter().any(|a| a.key == "aspect-ratio") {
2181− out.push_str(&format!(" style=\"aspect-ratio:{}/{}\"", w, h));
2182− }
2183− }
2184−
2185− // Smart image loading: first 3 images get fetchpriority="high" (above the fold),
2186− // subsequent images get loading="lazy" + decoding="async"
2187− ctx.image_count += 1;
2188− if ctx.image_count <= 3 {
2189− // Above-the-fold: eager loading with high priority
2190− if !elem.attrs.iter().any(|a| a.key == "fetchpriority") {
2191− out.push_str(" fetchpriority=\"high\"");
2192− }
2193− } else {
2194− // Below-the-fold: lazy loading
2195− if !elem.attrs.iter().any(|a| a.key == "loading") {
2196− out.push_str(" loading=\"lazy\"");
2197− }
2198− if !elem.attrs.iter().any(|a| a.key == "decoding") {
2199− out.push_str(" decoding=\"async\"");
2200− }
2201− }
2202− }
2203−
22041506 out.push('>');
22051507 out.push_str(ctx.nl());
22061508}
@@ -2216,7 +1518,10 @@ fn generate_text_segments(
22161518 TextSegment::Plain(text) => out.push_str(&html_escape(text)),
22171519 TextSegment::Inline(elem) => {
22181520 let mut buf = String::new();
2219− generate_element(elem, None, &mut buf, styles, ctx);
1521+ // An element inside a line of text is in text
1522+ let outer_flow = std::mem::take(&mut ctx.flow);
1523+ generate_element(elem, Some(Layout::Text), &mut buf, styles, ctx);
1524+ ctx.flow = outer_flow;
22201525 out.push_str(buf.trim_end());
22211526 }
22221527 }
@@ -2229,143 +1534,97 @@ fn generate_text_segments(
22291534
22301535fn compute_class(
22311536 attrs: &[Attribute],
2232− kind: &ElementKind,
2233− parent_kind: Option<&ElementKind>,
1537+ site: &Site,
22341538 styles: &mut StyleCollector,
2235− has_overlay_children: bool,
1539+ distinct: String,
22361540) -> Option<String> {
2237− let base = attrs_to_css(attrs, "", kind, parent_kind, has_overlay_children);
2238−
2239− // Collect pseudo-state overrides
2240− let mut pseudo = Vec::new();
2241− for &(prefix, selector) in PSEUDO_PREFIXES {
2242− let css = attrs_to_css(attrs, prefix, kind, parent_kind, has_overlay_children);
2243− if !css.is_empty() {
2244− pseudo.push((selector.to_string(), css));
2245− }
2246− }
2247−
2248− // Auto-add ::-webkit-scrollbar pseudo for no-scrollbar attribute
2249− if attrs.iter().any(|a| a.key == "no-scrollbar") {
2250− pseudo.push((
2251− "::-webkit-scrollbar".to_string(),
2252− "display:none;".to_string(),
2253− ));
2254− }
2255−
2256− // Collect nth:EXPR: dynamic pseudo selectors
2257− let mut nth_prefixes: Vec<String> = Vec::new();
2258− for attr in attrs {
2259− if attr.key.starts_with("nth:") {
2260− let rest = &attr.key[4..];
2261− if let Some(colon_pos) = rest.find(':') {
2262− let prefix = format!("nth:{}:", &rest[..colon_pos]);
2263− if !nth_prefixes.contains(&prefix) {
2264− nth_prefixes.push(prefix);
2265− }
2266− }
2267− }
2268− }
2269− for prefix in &nth_prefixes {
2270− let expr = &prefix[4..prefix.len() - 1];
2271− let selector = format!(":nth-child({})", expr);
2272− let css = attrs_to_css(attrs, prefix, kind, parent_kind, has_overlay_children);
2273− if !css.is_empty() {
2274− pseudo.push((selector, css));
1541+ // Every condition an attribute is under, and none
1542+ let mut conditions = vec![Condition::default()];
1543+ for attr in attrs.iter().filter(|a| !a.html) {
1544+ let (condition, _) = Condition::of(&attr.key);
1545+ if !conditions.contains(&condition) {
1546+ conditions.push(condition);
22751547 }
22761548 }
1549+ // Dedupe: if a property is declared twice within a single rule, keep only
1550+ // the last occurrence.
1551+ let rules: Vec<(Condition, String)> = conditions
1552+ .into_iter()
1553+ .map(|condition| {
1554+ let css = dedupe_declarations(&attrs_to_css(attrs, &condition, site));
1555+ (condition, css)
1556+ })
1557+ .collect();
1558+ // The kind's defaults, less what the element sets itself (a user
1559+ // `[list-style disc]` wins over the default `list-style:none` anyway,
1560+ // so there is no need to ship both)
1561+ let own = rules
1562+ .iter()
1563+ .find(|(condition, _)| *condition == Condition::default())
1564+ .map_or("", |(_, css)| css.as_str());
1565+ let own: Vec<&str> = declarations(own).map(|(name, _)| name).collect();
1566+ let defaults: String = declarations(&dedupe_declarations(&default_css(site)))
1567+ .filter(|(name, _)| !own.contains(name))
1568+ .map(|(_, declaration)| declaration)
1569+ .collect();
1570+ styles.get_class(defaults, rules, distinct)
1571+}
22771572
2278− // Collect has(...): dynamic pseudo selectors
2279− let mut has_prefixes: Vec<String> = Vec::new();
2280− for attr in attrs {
2281− if attr.key.starts_with("has(")
2282− && let Some(close) = attr.key.find("):")
2283− {
2284− let prefix = format!("{}:", &attr.key[..close + 1]);
2285− if !has_prefixes.contains(&prefix) {
2286− has_prefixes.push(prefix);
2287− }
2288− }
1573+/// The defaults of an element's kind where it is: an overlay's positioning
1574+/// context, its layout, and its kind's own CSS (a heading's `margin:0`).
1575+fn default_css(site: &Site) -> String {
1576+ let mut css = String::new();
1577+ // Elements with @in-front / @behind children become positioning
1578+ // contexts
1579+ if site.has_overlay_children {
1580+ css.push_str("position:relative;isolation:isolate;");
22891581 }
2290− for prefix in &has_prefixes {
2291− let inner = &prefix[4..prefix.len() - 2]; // extract selector from has(selector):
2292− let selector = format!(":has({})", inner);
2293− let css = attrs_to_css(attrs, prefix, kind, parent_kind, has_overlay_children);
2294− if !css.is_empty() {
2295− pseudo.push((selector, css));
2296− }
1582+ if !site.root {
1583+ css.push_str(layout_css(site.kind.layout(), site.inline));
22971584 }
1585+ css.push_str(site.kind.css());
1586+ css
1587+}
22981588
2299− // Collect responsive overrides
2300− let mut responsive = Vec::new();
2301− for &(bp_name, _) in BREAKPOINTS {
2302− let prefix = format!("{}:", bp_name);
2303− let css = attrs_to_css(attrs, &prefix, kind, parent_kind, has_overlay_children);
2304− if !css.is_empty() {
2305− responsive.push((bp_name.to_string(), css));
1589+/// The declarations of a rule body, as (property, `property:value;`), for
1590+/// bodies htmlang wrote: every declaration ends in `;`, and a `;` inside
1591+/// quotes or parentheses doesn't end one.
1592+fn declarations(css: &str) -> impl Iterator<Item = (&str, &str)> {
1593+ let mut rest = css;
1594+ std::iter::from_fn(move || {
1595+ if rest.is_empty() {
1596+ return None;
23061597 }
2307− }
2308−
2309− // Collect container query overrides
2310− let mut container = Vec::new();
2311− for &(bp_name, _) in BREAKPOINTS {
2312− let prefix = format!("cq-{}:", bp_name);
2313− let css = attrs_to_css(attrs, &prefix, kind, parent_kind, has_overlay_children);
2314− if !css.is_empty() {
2315− container.push((bp_name.to_string(), css));
1598+ let (mut depth, mut quote, mut escaped) = (0i32, None, false);
1599+ let mut end = rest.len();
1600+ for (i, c) in rest.char_indices() {
1601+ match c {
1602+ _ if escaped => escaped = false,
1603+ '\\' => escaped = true,
1604+ c if Some(c) == quote => quote = None,
1605+ _ if quote.is_some() => {}
1606+ '"' | '\'' => quote = Some(c),
1607+ '(' => depth += 1,
1608+ ')' => depth -= 1,
1609+ ';' if depth == 0 => {
1610+ end = i + 1;
1611+ break;
1612+ }
1613+ _ => {}
1614+ }
23161615 }
2317− }
2318−
2319− let dark = attrs_to_css(attrs, "dark:", kind, parent_kind, has_overlay_children);
2320− let print = attrs_to_css(attrs, "print:", kind, parent_kind, has_overlay_children);
2321− let motion_safe = attrs_to_css(attrs, "motion-safe:", kind, parent_kind, has_overlay_children);
2322− let motion_reduce =
2323− attrs_to_css(attrs, "motion-reduce:", kind, parent_kind, has_overlay_children);
2324− let landscape = attrs_to_css(attrs, "landscape:", kind, parent_kind, has_overlay_children);
2325− let portrait = attrs_to_css(attrs, "portrait:", kind, parent_kind, has_overlay_children);
2326−
2327− // Dedupe: if a property is declared twice within a single rule, keep only
2328− // the last occurrence (element-kind defaults are written before
2329− // user attributes, so a user [list-style disc] correctly overrides the
2330− // default list-style:none, and we don't need to ship both).
2331− let base = dedupe_declarations(&base);
2332− let pseudo: Vec<(String, String)> = pseudo
2333− .into_iter()
2334− .map(|(sel, css)| (sel, dedupe_declarations(&css)))
2335− .collect();
2336− let responsive: Vec<(String, String)> = responsive
2337− .into_iter()
2338− .map(|(bp, css)| (bp, dedupe_declarations(&css)))
2339− .collect();
2340− let dark = dedupe_declarations(&dark);
2341− let print = dedupe_declarations(&print);
2342− let motion_safe = dedupe_declarations(&motion_safe);
2343− let motion_reduce = dedupe_declarations(&motion_reduce);
2344− let landscape = dedupe_declarations(&landscape);
2345− let portrait = dedupe_declarations(&portrait);
2346− let container: Vec<(String, String)> = container
2347− .into_iter()
2348− .map(|(bp, css)| (bp, dedupe_declarations(&css)))
2349− .collect();
2350−
2351− styles.get_class(
2352− base,
2353− pseudo,
2354− responsive,
2355− dark,
2356− print,
2357− motion_safe,
2358− motion_reduce,
2359− landscape,
2360− portrait,
2361− container,
2362− )
1616+ let (declaration, after) = rest.split_at(end);
1617+ rest = after;
1618+ let name = declaration.split(':').next().unwrap_or("").trim();
1619+ Some((name, declaration))
1620+ })
23631621}
23641622
23651623/// Dedupe CSS declarations within a single rule body: for any property
23661624/// declared more than once, keep only the last occurrence. Unparseable
2367−/// segments (no `:`) are preserved as-is. Semicolons inside parentheses are
2368−/// treated as part of a value, not as declaration separators.
1625+/// segments (no `:`) are preserved as-is. Semicolons inside parentheses or
1626+/// quoted strings are treated as part of a value, not as declaration
1627+/// separators.
23691628fn dedupe_declarations(css: &str) -> String {
23701629 if css.is_empty() {
23711630 return String::new();
@@ -2380,8 +1639,26 @@ fn dedupe_declarations(css: &str) -> String {
23801639 let mut decls: Vec<(Option<String>, String)> = Vec::new();
23811640 let mut current = String::new();
23821641 let mut depth: i32 = 0;
1642+ // A quoted string's `;` (`content "a;b"`) is text; a backslash escapes
1643+ // the character after it
1644+ let mut quote: Option<char> = None;
1645+ let mut escaped = false;
23831646 for ch in css.chars() {
2384− if ch == '(' {
1647+ if escaped {
1648+ escaped = false;
1649+ current.push(ch);
1650+ } else if ch == '\\' {
1651+ escaped = true;
1652+ current.push(ch);
1653+ } else if let Some(q) = quote {
1654+ if ch == q {
1655+ quote = None;
1656+ }
1657+ current.push(ch);
1658+ } else if ch == '"' || ch == '\'' {
1659+ quote = Some(ch);
1660+ current.push(ch);
1661+ } else if ch == '(' {
23851662 depth += 1;
23861663 current.push(ch);
23871664 } else if ch == ')' {
@@ -2463,1280 +1740,578 @@ fn emit_class_attr(out: &mut String, gen_class: Option<&str>, user_class: Option
24631740// Attribute → CSS mapping
24641741// ---------------------------------------------------------------------------
24651742
2466−/// (htmlang prefix, CSS selector suffix)
2467−const PSEUDO_PREFIXES: &[(&str, &str)] = &[
2468− ("hover:", ":hover"),
2469− ("active:", ":active"),
2470− ("focus:", ":focus"),
2471− ("focus-visible:", ":focus-visible"),
2472− ("focus-within:", ":focus-within"),
2473− ("disabled:", ":disabled"),
2474− ("checked:", ":checked"),
2475− ("placeholder:", "::placeholder"),
2476− ("first:", ":first-child"),
2477− ("last:", ":last-child"),
2478− ("odd:", ":nth-child(odd)"),
2479− ("even:", ":nth-child(even)"),
2480− ("before:", "::before"),
2481− ("after:", "::after"),
2482− ("selection:", "::selection"),
2483− ("visited:", ":visited"),
2484− ("empty:", ":empty"),
2485− ("target:", ":target"),
2486− ("valid:", ":valid"),
2487− ("invalid:", ":invalid"),
2488−];
2489−const RESPONSIVE_PREFIXES: &[&str] = &["sm:", "md:", "lg:", "xl:", "2xl:"];
2490−const MEDIA_PREFIXES: &[&str] = &[
2491− "dark:",
2492− "print:",
2493− "motion-safe:",
2494− "motion-reduce:",
2495− "landscape:",
2496− "portrait:",
2497−];
2498−const CONTAINER_QUERY_PREFIXES: &[&str] = &["cq-sm:", "cq-md:", "cq-lg:", "cq-xl:", "cq-2xl:"];
2499−
2500−fn is_prefixed_attr(key: &str) -> bool {
2501− PSEUDO_PREFIXES.iter().any(|&(p, _)| key.starts_with(p))
2502− || RESPONSIVE_PREFIXES.iter().any(|p| key.starts_with(p))
2503− || MEDIA_PREFIXES.iter().any(|p| key.starts_with(p))
2504− || CONTAINER_QUERY_PREFIXES.iter().any(|p| key.starts_with(p))
2505− || key.starts_with("nth:")
2506− || key.starts_with("has(")
1743+/// Where an element is written, which its CSS depends on.
1744+struct Site<'a> {
1745+ kind: &'a ElementKind,
1746+ /// How its parent lays out its children: its `width fill`, `height
1747+ /// fill` and `shrink` compile against it.
1748+ parent: &'a Flow,
1749+ /// It has `@in-front` / `@behind` children.
1750+ has_overlay_children: bool,
1751+ /// A row, column or grid inside text, laid out inline.
1752+ inline: bool,
1753+ /// The page's `<body>`, which the reset already makes a column.
1754+ root: bool,
25071755}
25081756
2509−/// `display:flex;flex-direction:column;` — base layout for `@el` and every
2510−/// semantic wrapper that behaves like a column.
2511−const FLEX_COLUMN: &str = "display:flex;flex-direction:column;";
1757+impl Site<'_> {
1758+ /// Where an element in a parent with the layout `layout` and the flow
1759+ /// `parent` is.
1760+ fn new<'a>(elem: &'a Element, layout: Option<Layout>, parent: &'a Flow) -> Site<'a> {
1761+ Site {
1762+ kind: &elem.kind,
1763+ parent,
1764+ has_overlay_children: has_overlay_children(elem),
1765+ inline: layout == Some(Layout::Text) && elem.kind.layout().is_container(),
1766+ root: false,
1767+ }
1768+ }
1769+}
25121770
2513−/// Font stack shared by `@pre`, `@code`, `@kbd`.
2514−const MONOSPACE_STACK: &str = "font-family:ui-monospace,monospace;";
1771+// ---------------------------------------------------------------------------
1772+// Direction: what a child's `fill` and `shrink` compile against
1773+// ---------------------------------------------------------------------------
25151774
2516−/// Declarations common to `@badge` and `@tag`. They differ only in
2517−/// `border-radius` (and `@badge` additionally centers content / pins
2518−/// line-height:1), so keeping the shared base here avoids drift.
2519−const PILL_BASE: &str =
2520− "display:inline-flex;align-items:center;padding:2px 8px;font-size:0.75rem;font-weight:600;";
1775+/// The way a flex row or column lays out its children.
1776+#[derive(Clone, Copy, PartialEq, Eq, Debug)]
1777+enum Axis {
1778+ Row,
1779+ Column,
1780+}
25211781
2522−fn attrs_to_css(
2523− attrs: &[Attribute],
2524− state_prefix: &str,
2525− kind: &ElementKind,
2526− parent_kind: Option<&ElementKind>,
2527− has_overlay_children: bool,
2528−) -> String {
2529− let mut css = String::new();
1782+impl Axis {
1783+ /// The direction a `flex-direction` or `flex-flow` value sets, if it
1784+ /// names one (not `var(--dir)`, which only the browser knows).
1785+ fn of_value(value: &str) -> Option<Axis> {
1786+ value.split_whitespace().find_map(|word| match word {
1787+ "row" | "row-reverse" => Some(Axis::Row),
1788+ "column" | "column-reverse" => Some(Axis::Column),
1789+ _ => None,
1790+ })
1791+ }
1792+}
25301793
2531− // Base element styles only for the default (non-state) pass
2532− if state_prefix.is_empty() {
2533− // Elements with @in-front / @behind children become positioning
2534− // contexts. Pushed before user attrs so an explicit `position` wins
2535− // via dedupe (only the last declaration of a property is kept).
2536− if has_overlay_children {
2537− css.push_str("position:relative;isolation:isolate;");
2538− }
2539− match kind {
2540− ElementKind::Row => css.push_str("display:flex;flex-direction:row;"),
2541− ElementKind::Column
2542− | ElementKind::El
2543− // Semantic elements get flex column layout like @el
2544− | ElementKind::Nav
2545− | ElementKind::Header
2546− | ElementKind::Footer
2547− | ElementKind::Main
2548− | ElementKind::Section
2549− | ElementKind::Article
2550− | ElementKind::Aside
2551− | ElementKind::ListItem
2552− | ElementKind::Form
2553− | ElementKind::Details
2554− | ElementKind::Dialog => css.push_str(FLEX_COLUMN),
2555− ElementKind::Paragraph
2556− | ElementKind::H1
2557− | ElementKind::H2
2558− | ElementKind::H3
2559− | ElementKind::H4
2560− | ElementKind::H5
2561− | ElementKind::H6 => css.push_str("margin:0;"),
2562− // Lists: reset browser defaults
2563− ElementKind::List => css.push_str("margin:0;padding-left:0;list-style:none;"),
2564− // Figure / Blockquote: flex column with browser margin reset
2565− ElementKind::Figure | ElementKind::Blockquote => {
2566− css.push_str(FLEX_COLUMN);
2567− css.push_str("margin:0;");
2568− }
2569− // Pre: preserve whitespace
2570− ElementKind::Pre => {
2571− css.push_str("margin:0;white-space:pre;");
2572− css.push_str(MONOSPACE_STACK);
2573− }
2574− // Code / Kbd: monospace font
2575− ElementKind::Code | ElementKind::Kbd => css.push_str(MONOSPACE_STACK),
2576− ElementKind::DefinitionList => css.push_str("margin:0;"),
2577− ElementKind::DefinitionDescription => {
2578− css.push_str("margin:0;");
2579− css.push_str(FLEX_COLUMN);
2580− }
2581− ElementKind::Fieldset => {
2582− css.push_str(FLEX_COLUMN);
2583− // Align padding to the px-based scale used by Badge/Tag/Chip
2584− // rather than the old 0.5em (which depended on font-size).
2585− css.push_str("border:1px solid currentColor;padding:8px;margin:0;");
2586− }
2587− ElementKind::Grid => css.push_str("display:grid;"),
2588− ElementKind::Stack => css.push_str("position:relative;"),
2589− ElementKind::Badge => {
2590− css.push_str(PILL_BASE);
2591− css.push_str("justify-content:center;border-radius:9999px;line-height:1;");
2592− }
2593− ElementKind::Tag => {
2594− css.push_str(PILL_BASE);
2595− css.push_str("border-radius:4px;");
2596− }
2597− ElementKind::Tooltip => css.push_str("position:relative;cursor:help;"),
2598− ElementKind::Spacer => css.push_str("flex:1;"),
2599− ElementKind::Avatar => css.push_str("display:inline-flex;align-items:center;justify-content:center;border-radius:9999px;overflow:hidden;flex-shrink:0;"),
2600− ElementKind::Carousel => css.push_str("display:flex;flex-direction:row;overflow-x:auto;scroll-snap-type:x mandatory;-webkit-overflow-scrolling:touch;scrollbar-width:none;"),
2601− ElementKind::Chip => css.push_str("display:inline-flex;align-items:center;gap:4px;padding:4px 12px;border-radius:9999px;font-size:0.875rem;border:1px solid currentColor;"),
2602− // Overlay layers fill the parent. Parent gets position:relative
2603− // applied automatically (see has_overlay_children check below).
2604− ElementKind::InFront => {
2605− css.push_str(FLEX_COLUMN);
2606− css.push_str("position:absolute;inset:0;");
1794+/// How an element lays out its children, as its CSS sets it: the
1795+/// direction its children's `width`/`height` `fill` and `shrink` compile
1796+/// against. That is the direction of `@row` or of a column, or the one its
1797+/// own `flex-direction` (or `flex-flow`) sets, with or without media or
1798+/// container prefixes. Like elm-ui's `.r > .wf`, the rules for a direction
1799+/// set under a prefix are keyed on the element's class: `@media (...) {
1800+/// :where(.a)>.b {...} }`.
1801+#[derive(Clone, Default)]
1802+struct Flow {
1803+ /// Without a prefix; `None` when the element isn't a flex row or column
1804+ /// (a grid, text, HTML's own layout, the top of the page)
1805+ base: Option<Axis>,
1806+ /// The direction under each chain of at-rule prefixes that sets one, in
1807+ /// the order their blocks are written
1808+ changes: Vec<(Vec<usize>, Axis)>,
1809+ /// The element's generated class, which the rules for the changes are
1810+ /// keyed on
1811+ class: Option<String>,
1812+}
1813+
1814+impl Flow {
1815+ fn of(elem: &Element) -> Flow {
1816+ let mut base = match elem.kind.layout() {
1817+ Layout::Row => Axis::Row,
1818+ Layout::Column => Axis::Column,
1819+ _ => return Flow::default(),
1820+ };
1821+ let mut changes: Vec<(Vec<usize>, Axis)> = Vec::new();
1822+ for attr in elem.attrs.iter().filter(|a| !a.html) {
1823+ let (condition, name) = Condition::of(&attr.key);
1824+ if !matches!(name, "flex-direction" | "flex-flow") || !condition.selector.is_empty() {
1825+ continue;
26071826 }
2608− ElementKind::Behind => {
2609− css.push_str(FLEX_COLUMN);
2610− css.push_str("position:absolute;inset:0;z-index:-1;");
1827+ let Some(axis) = attr.value.as_deref().and_then(Axis::of_value) else {
1828+ continue;
1829+ };
1830+ if condition.at.is_empty() {
1831+ base = axis;
1832+ } else {
1833+ // The later one wins, as in the CSS
1834+ changes.retain(|(at, _)| *at != condition.at);
1835+ changes.push((condition.at, axis));
26111836 }
2612− _ => {}
26131837 }
2614− // Children of @carousel get scroll-snap-align and flex-shrink
2615− if matches!(parent_kind, Some(ElementKind::Carousel)) {
2616− css.push_str("scroll-snap-align:start;flex-shrink:0;");
1838+ changes.sort_by_key(|(at, _)| at_order(at));
1839+ Flow {
1840+ base: Some(base),
1841+ changes,
1842+ class: None,
1843+ }
1844+ }
1845+
1846+ /// The direction under the at-rules `at`: the latest one set among
1847+ /// the conditions that hold there (`md:` holds at `lg:`), else the one
1848+ /// without a prefix.
1849+ fn at(&self, at: &[usize]) -> Option<Axis> {
1850+ let base = self.base?;
1851+ let here = Condition::at_only(at);
1852+ let changed = self
1853+ .changes
1854+ .iter()
1855+ .rev()
1856+ .find(|(chain, _)| Condition::at_only(chain).holds_at(&here))
1857+ .map(|&(_, axis)| axis);
1858+ Some(changed.unwrap_or(base))
1859+ }
1860+}
1861+
1862+/// `width` or `height`.
1863+#[derive(Clone, Copy, PartialEq, Eq)]
1864+enum Dim {
1865+ Width,
1866+ Height,
1867+}
1868+
1869+/// What a `width` or `height` says.
1870+#[derive(Clone, Copy, PartialEq, Eq)]
1871+enum Size {
1872+ Fill,
1873+ Shrink,
1874+ /// A size of its own (`width 300`)
1875+ Set,
1876+}
1877+
1878+impl Size {
1879+ fn of(value: &str) -> Size {
1880+ match value.trim() {
1881+ "fill" => Size::Fill,
1882+ "shrink" => Size::Shrink,
1883+ _ => Size::Set,
26171884 }
26181885 }
1886+}
1887+
1888+/// The declarations `fill` and `shrink` make in a parent laid out along
1889+/// `axis` (`None`: not a flex row or column). Along the parent's direction,
1890+/// `fill` takes the remaining space and `shrink` keeps the content's size;
1891+/// across it (or outside flex), `fill` is the full size and `shrink` fits
1892+/// the content.
1893+fn sizing(dim: Dim, size: Size, axis: Option<Axis>) -> &'static [(&'static str, &'static str)] {
1894+ match (dim, size, axis) {
1895+ (_, Size::Set, _) => &[],
1896+ (Dim::Width, Size::Fill, Some(Axis::Row)) => &[("flex", "1"), ("min-width", "0")],
1897+ (Dim::Width, Size::Fill, _) => &[("width", "100%")],
1898+ (Dim::Width, Size::Shrink, Some(Axis::Row)) => &[("flex-shrink", "0")],
1899+ (Dim::Width, Size::Shrink, _) => &[("width", "fit-content")],
1900+ (Dim::Height, Size::Fill, Some(Axis::Column)) => &[("flex", "1"), ("min-height", "0")],
1901+ (Dim::Height, Size::Fill, _) => &[("height", "100%")],
1902+ (Dim::Height, Size::Shrink, Some(Axis::Column)) => &[("flex-shrink", "0")],
1903+ (Dim::Height, Size::Shrink, _) => &[("height", "fit-content")],
1904+ }
1905+}
1906+
1907+/// Every property `fill` and `shrink` of `dim` can set, with its initial
1908+/// value (`flex` covers `flex-shrink`).
1909+fn sizing_properties(dim: Dim) -> [(&'static str, &'static str); 3] {
1910+ match dim {
1911+ Dim::Width => [
1912+ ("flex", "0 1 auto"),
1913+ ("min-width", "auto"),
1914+ ("width", "auto"),
1915+ ],
1916+ Dim::Height => [
1917+ ("flex", "0 1 auto"),
1918+ ("min-height", "auto"),
1919+ ("height", "auto"),
1920+ ],
1921+ }
1922+}
26191923
2620− for attr in attrs {
2621− // Determine the effective key for this pass
2622− let effective_key = if state_prefix.is_empty() {
2623− if is_prefixed_attr(&attr.key) {
1924+/// What an element's attributes under some prefixes say about its size.
1925+#[derive(Default)]
1926+struct Sizes {
1927+ /// The last `width` and `height`
1928+ width: Option<Size>,
1929+ height: Option<Size>,
1930+ /// A `fill` or `shrink` for the width / height is among them (a later
1931+ /// size may replace it)
1932+ width_word: bool,
1933+ height_word: bool,
1934+ /// It writes `flex`, one of its longhands (`flex-grow`, `flex-shrink`,
1935+ /// `flex-basis`), `min-width` or `min-height` itself
1936+ flex: bool,
1937+ flex_grow: bool,
1938+ flex_shrink: bool,
1939+ flex_basis: bool,
1940+ min_width: bool,
1941+ min_height: bool,
1942+}
1943+
1944+impl Sizes {
1945+ /// Read the attributes under the conditions that hold wherever `at`
1946+ /// does, a later condition over an earlier one.
1947+ fn of(attrs: &[Attribute], at: &Condition) -> Sizes {
1948+ let mut sizes = Sizes::default();
1949+ let mut read: Vec<(Condition, &str, &str)> = Vec::new();
1950+ for attr in attrs.iter().filter(|a| !a.html) {
1951+ let (condition, name) = Condition::of(&attr.key);
1952+ let Some(value) = attr.value.as_deref().filter(|v| !v.trim().is_empty()) else {
26241953 continue;
1954+ };
1955+ if condition.holds_at(at) {
1956+ read.push((condition, name, value));
1957+ }
1958+ }
1959+ read.sort_by_cached_key(|(condition, _, _)| condition.order());
1960+ for (_, name, value) in read {
1961+ match name {
1962+ "width" => {
1963+ let size = Size::of(value);
1964+ sizes.width = Some(size);
1965+ sizes.width_word |= size != Size::Set;
1966+ }
1967+ "height" => {
1968+ let size = Size::of(value);
1969+ sizes.height = Some(size);
1970+ sizes.height_word |= size != Size::Set;
1971+ }
1972+ "flex" => sizes.flex = true,
1973+ "flex-grow" => sizes.flex_grow = true,
1974+ "flex-shrink" => sizes.flex_shrink = true,
1975+ "flex-basis" => sizes.flex_basis = true,
1976+ "min-width" => sizes.min_width = true,
1977+ "min-height" => sizes.min_height = true,
1978+ _ => {}
26251979 }
2626− attr.key.as_str()
2627− } else {
2628− match attr.key.strip_prefix(state_prefix) {
2629− Some(k) => k,
2630− None => continue,
1980+ }
1981+ sizes
1982+ }
1983+
1984+ /// The element writes `property` itself: a layout word leaves it alone.
1985+ fn writes(&self, property: &str) -> bool {
1986+ match property {
1987+ "flex" => self.flex,
1988+ "flex-grow" => self.flex || self.flex_grow,
1989+ "flex-shrink" => self.flex || self.flex_shrink,
1990+ "flex-basis" => self.flex || self.flex_basis,
1991+ "min-width" => self.min_width,
1992+ "min-height" => self.min_height,
1993+ "width" => self.width == Some(Size::Set),
1994+ "height" => self.height == Some(Size::Set),
1995+ _ => false,
1996+ }
1997+ }
1998+
1999+ /// Write a layout word's `property: value`, unless the element writes
2000+ /// the property itself. When it writes some of `flex`'s longhands, a
2001+ /// `flex` is written as the others (`flex-shrink 0, width fill` still
2002+ /// grows).
2003+ fn push(&self, css: &mut String, property: &str, value: &str) {
2004+ if property == "flex" && !self.flex {
2005+ let longhands = match value {
2006+ "1" => [
2007+ ("flex-grow", "1"),
2008+ ("flex-shrink", "1"),
2009+ ("flex-basis", "0%"),
2010+ ],
2011+ // The reset, `0 1 auto`
2012+ _ => [
2013+ ("flex-grow", "0"),
2014+ ("flex-shrink", "1"),
2015+ ("flex-basis", "auto"),
2016+ ],
2017+ };
2018+ if longhands.iter().any(|&(p, _)| self.writes(p)) {
2019+ for (longhand, value) in longhands {
2020+ if !self.writes(longhand) {
2021+ push_css(css, longhand, value);
2022+ }
2023+ }
2024+ return;
26312025 }
2026+ }
2027+ if !self.writes(property) {
2028+ push_css(css, property, value);
2029+ }
2030+ }
2031+}
2032+
2033+/// The rule that gives an element's `fill` and `shrink`, as its attributes
2034+/// under the at-rules `at` set them, their meaning in a parent laid out
2035+/// along `axis`. Every other property a layout word could have set is put
2036+/// back to its initial value, so the rule is right whichever earlier rule
2037+/// it overrides. Properties the element writes itself are left alone.
2038+fn sizing_rule(attrs: &[Attribute], at: &[usize], axis: Axis) -> String {
2039+ let sizes = Sizes::of(attrs, &Condition::at_only(at));
2040+ let mut sets: Vec<(&str, &str)> = Vec::new();
2041+ let mut resets: Vec<(&str, &str)> = Vec::new();
2042+ for (dim, size, word) in [
2043+ (Dim::Width, sizes.width, sizes.width_word),
2044+ (Dim::Height, sizes.height, sizes.height_word),
2045+ ] {
2046+ if !word {
2047+ continue;
2048+ }
2049+ if let Some(size) = size {
2050+ sets.extend_from_slice(sizing(dim, size, Some(axis)));
2051+ }
2052+ resets.extend_from_slice(&sizing_properties(dim));
2053+ }
2054+ let mut css = String::new();
2055+ let mut written: Vec<&str> = Vec::new();
2056+ for &(property, value) in &resets {
2057+ if sets.iter().any(|&(p, _)| p == property) || written.contains(&property) {
2058+ continue;
2059+ }
2060+ written.push(property);
2061+ sizes.push(&mut css, property, value);
2062+ }
2063+ for &(property, value) in &sets {
2064+ sizes.push(&mut css, property, value);
2065+ }
2066+ css
2067+}
2068+
2069+/// The rules an element's `fill` and `shrink` need under each chain of
2070+/// at-rules where the direction of `flow` (its parent's) changes: `(at,
2071+/// body)`.
2072+fn sizing_changes(attrs: &[Attribute], flow: &Flow) -> Vec<(Vec<usize>, String)> {
2073+ flow.changes
2074+ .iter()
2075+ .map(|(at, axis)| (at.clone(), sizing_rule(attrs, at, *axis)))
2076+ .filter(|(_, body)| !body.is_empty())
2077+ .collect()
2078+}
2079+
2080+/// An element's generated class, with the rules keyed on its parent's
2081+/// class that its `fill` and `shrink` need where the parent's direction
2082+/// changes under a prefix (see [`Flow`]): `:where(.a)>.b`, one class of
2083+/// specificity like any class rule.
2084+fn element_class(elem: &Element, site: &Site, styles: &mut StyleCollector) -> Option<String> {
2085+ let as_child = match site.parent.class {
2086+ Some(_) => sizing_changes(&elem.attrs, site.parent),
2087+ None => Vec::new(),
2088+ };
2089+ // Two elements with the same CSS but different rules keyed on them
2090+ // need two classes
2091+ let mut distinct = String::new();
2092+ for (at, body) in &as_child {
2093+ distinct.push_str(&format!("<{:?}{}", at, body));
2094+ }
2095+ let class = compute_class(&elem.attrs, site, styles, distinct)?;
2096+ if let Some(parent) = &site.parent.class {
2097+ for (at, body) in as_child {
2098+ styles.add_keyed(at, format!(":where(.{})>.{}", parent, class), body);
2099+ }
2100+ }
2101+ Some(class)
2102+}
2103+
2104+/// The `display` of a layout (nothing for text, native and void elements,
2105+/// which keep HTML's own).
2106+fn layout_css(layout: Layout, inline: bool) -> &'static str {
2107+ match (layout, inline) {
2108+ (Layout::Column, false) => "display:flex;flex-direction:column;",
2109+ (Layout::Column, true) => "display:inline-flex;flex-direction:column;",
2110+ (Layout::Row, false) => "display:flex;flex-direction:row;",
2111+ (Layout::Row, true) => "display:inline-flex;flex-direction:row;",
2112+ (Layout::Grid, false) => "display:grid;",
2113+ (Layout::Grid, true) => "display:inline-grid;",
2114+ _ => "",
2115+ }
2116+}
2117+
2118+/// The declarations of the attributes under `condition` (the defaults of
2119+/// the element's kind are [`default_css`]'s).
2120+fn attrs_to_css(attrs: &[Attribute], condition: &Condition, site: &Site) -> String {
2121+ let mut css = String::new();
2122+ // The auto margins of `center-x`, `align-left`, ..., written at the end
2123+ let mut aligned = String::new();
2124+ let kind = site.kind;
2125+ // Under `children:` the styles go on the children, whose parent is this
2126+ // element: htmlang's words that place an element in its parent are an
2127+ // error there (the parser reports them), and left out
2128+ let on_children = condition.on_children();
2129+ let inside = condition.inside().is_some();
2130+ // The direction `fill` and `shrink` compile against
2131+ let axis = site.parent.at(&condition.at);
2132+
2133+ // htmlang's words for laying out children (`spacing`, `wrap`,
2134+ // `grid-cols`) mean nothing on an element that doesn't lay out its
2135+ // children, which the parser reports; they are left out. Under
2136+ // `children:` they go on the children, whose layout isn't known here.
2137+ let lays_out_children = kind.layout().is_container() || on_children;
2138+ fn under<'k>(key: &'k str, condition: &Condition) -> Option<&'k str> {
2139+ let (c, name) = Condition::of(key);
2140+ (c == *condition).then_some(name)
2141+ }
2142+
2143+ for (index, attr) in attrs.iter().enumerate() {
2144+ if attr.html {
2145+ continue;
2146+ }
2147+ let Some(effective_key) = under(&attr.key, condition) else {
2148+ continue;
26322149 };
2150+ if on_children && crate::vocab::places_in_parent(effective_key, attr.value.as_deref()) {
2151+ continue;
2152+ }
2153+ // Under an element prefix (`@td:`) the styles go on elements whose
2154+ // layout and parent aren't known here: htmlang's own words are an
2155+ // error there (the parser reports them), and left out
2156+ if inside && crate::vocab::is_htmlang_word(effective_key, attr.value.as_deref()) {
2157+ continue;
2158+ }
26332159
26342160 let val = attr.value.as_deref();
2161+ // A style whose value came out empty (a field a record doesn't
2162+ // have, `${if()}` without its other branch) is left out
2163+ if val.is_some_and(|v| v.trim().is_empty()) {
2164+ continue;
2165+ }
26352166
26362167 match effective_key {
2637− // Layout
2638− "spacing" | "gap" => {
2639− if let Some(v) = val {
2640− push_css(&mut css, "gap", &css_px(v));
2641− }
2642− }
2643− "padding" => {
2644− if let Some(v) = val {
2645− push_css(&mut css, "padding", &css_px_multi(v));
2646− }
2647− }
2648− "padding-x" => {
2649− if let Some(v) = val {
2650− // Logical property covers both inline sides in one
2651− // declaration; for symmetric values this is visually
2652− // identical to padding-left/right in LTR and RTL.
2653− push_css(&mut css, "padding-inline", &css_px(v));
2654− }
2655− }
2656− "padding-y" => {
2657− if let Some(v) = val {
2658− push_css(&mut css, "padding-block", &css_px(v));
2659− }
2660− }
2661− "padding-top" => {
2662− if let Some(v) = val {
2663− push_css(&mut css, "padding-top", &css_px(v));
2664− }
2665− }
2666− "padding-bottom" => {
2667− if let Some(v) = val {
2668− push_css(&mut css, "padding-bottom", &css_px(v));
2669− }
2670− }
2671− "padding-left" => {
2168+ // htmlang's own words: they lay out children or place the
2169+ // element in its parent, and mean more than one CSS property
2170+ "spacing" if !lays_out_children => {}
2171+ "spacing" => {
26722172 if let Some(v) = val {
2673− push_css(&mut css, "padding-left", &css_px(v));
2674− }
2675− }
2676− "padding-right" => {
2677− if let Some(v) = val {
2678− push_css(&mut css, "padding-right", &css_px(v));
2173+ push_css(&mut css, "gap", &with_px("gap", v));
26792174 }
26802175 }
26812176
2682− // Sizing
2683− "width" => {
2684− if let Some(v) = val {
2685− match v {
2686− "fill" => match parent_kind {
2687− Some(ElementKind::Row) => {
2688− push_css(&mut css, "flex", "1");
2689− push_css(&mut css, "min-width", "0");
2690− }
2691− _ => push_css(&mut css, "width", "100%"),
2692− },
2693− "shrink" => push_css(&mut css, "flex-shrink", "0"),
2694− _ => push_css(&mut css, "width", &css_px(v)),
2695− }
2177+ // Sizing: `fill` and `shrink` compile against the parent's
2178+ // direction. Only the last `width` (`height`) counts, as for
2179+ // any style written twice.
2180+ "width" | "height" if val.is_some_and(|v| Size::of(v) != Size::Set) => {
2181+ let later = attrs[index + 1..].iter().any(|a| {
2182+ !a.html
2183+ && under(&a.key, condition) == Some(effective_key)
2184+ && a.value.as_deref().is_some_and(|v| !v.trim().is_empty())
2185+ });
2186+ if later {
2187+ continue;
26962188 }
2697− }
2698− "height" => {
2699− if let Some(v) = val {
2700− match v {
2701− "fill" => match parent_kind {
2702− Some(ElementKind::Column) => {
2703− push_css(&mut css, "flex", "1");
2704− push_css(&mut css, "min-height", "0");
2705− }
2706− _ => push_css(&mut css, "height", "100%"),
2707− },
2708− "shrink" => push_css(&mut css, "flex-shrink", "0"),
2709− _ => push_css(&mut css, "height", &css_px(v)),
2189+ let dim = if effective_key == "width" {
2190+ Dim::Width
2191+ } else {
2192+ Dim::Height
2193+ };
2194+ let size = Size::of(val.unwrap_or_default());
2195+ // What the element writes itself, which a layout word
2196+ // leaves alone
2197+ let sizes = Sizes::of(attrs, condition);
2198+ for &(property, value) in sizing(dim, size, axis) {
2199+ sizes.push(&mut css, property, value);
2200+ }
2201+ }
2202+
2203+ // A size of its own under a prefix, where a `fill` or
2204+ // `shrink` that sets `flex` (along a flex parent's direction)
2205+ // holds too: the word's `flex` and minimum are put back, so the
2206+ // size is the one the element gets (`width fill, lg:width 200`
2207+ // in a row)
2208+ "width" | "height"
2209+ if *condition != Condition::default()
2210+ && attrs.iter().any(|a| {
2211+ let (c, name) = Condition::of(&a.key);
2212+ let along = match site.parent.at(&c.at) {
2213+ Some(Axis::Row) => name == "width",
2214+ Some(Axis::Column) => name == "height",
2215+ None => false,
2216+ };
2217+ !a.html
2218+ && name == effective_key
2219+ && along
2220+ && c != *condition
2221+ && c.holds_at(condition)
2222+ && a.value
2223+ .as_deref()
2224+ .is_some_and(|v| !v.trim().is_empty() && Size::of(v) != Size::Set)
2225+ }) =>
2226+ {
2227+ let dim = if effective_key == "width" {
2228+ Dim::Width
2229+ } else {
2230+ Dim::Height
2231+ };
2232+ let sizes = Sizes::of(attrs, condition);
2233+ for (property, value) in sizing_properties(dim) {
2234+ if property != effective_key {
2235+ sizes.push(&mut css, property, value);
27102236 }
27112237 }
2712− }
2713− "min-width" => {
2714− if let Some(v) = val {
2715− push_css(&mut css, "min-width", &css_px(v));
2716− }
2717− }
2718− "max-width" => {
2719− if let Some(v) = val {
2720− push_css(&mut css, "max-width", &css_px(v));
2721− }
2722− }
2723− "min-height" => {
27242238 if let Some(v) = val {
2725− push_css(&mut css, "min-height", &css_px(v));
2726− }
2727− }
2728− "max-height" => {
2729− if let Some(v) = val {
2730− push_css(&mut css, "max-height", &css_px(v));
2239+ push_css(&mut css, effective_key, &with_px(effective_key, v));
27312240 }
27322241 }
27332242
2734− // Alignment
2735− "center-x" => match parent_kind {
2736− Some(ElementKind::Column) | Some(ElementKind::El) => {
2737− push_css(&mut css, "align-self", "center");
2738− }
2739− _ => {
2740− push_css(&mut css, "margin-left", "auto");
2741− push_css(&mut css, "margin-right", "auto");
2742− }
2743− },
2744− "center-y" => match parent_kind {
2745− Some(ElementKind::Row) => push_css(&mut css, "align-self", "center"),
2746− _ => {
2747− push_css(&mut css, "margin-top", "auto");
2748− push_css(&mut css, "margin-bottom", "auto");
2749− }
2750− },
2751− "align-left" => match parent_kind {
2752− Some(ElementKind::Column) | Some(ElementKind::El) => {
2753− push_css(&mut css, "align-self", "flex-start");
2754− }
2755− _ => push_css(&mut css, "margin-right", "auto"),
2756− },
2757− "align-right" => match parent_kind {
2758− Some(ElementKind::Column) | Some(ElementKind::El) => {
2759− push_css(&mut css, "align-self", "flex-end");
2760− }
2761− _ => push_css(&mut css, "margin-left", "auto"),
2762− },
2763− "align-top" => match parent_kind {
2764− Some(ElementKind::Row) => push_css(&mut css, "align-self", "flex-start"),
2765− _ => push_css(&mut css, "margin-bottom", "auto"),
2766− },
2767− "align-bottom" => match parent_kind {
2768− Some(ElementKind::Row) => push_css(&mut css, "align-self", "flex-end"),
2769− _ => push_css(&mut css, "margin-top", "auto"),
2770− },
2771−
2772− // Style
2773− "background" => {
2774− if let Some(v) = val {
2775− push_css(&mut css, "background", v);
2776− }
2243+ // Alignment: auto margins, which work along either direction.
2244+ // They are written last, so a `margin` on the same element
2245+ // keeps its other sides (`center-x, margin 20`)
2246+ "center-x" => {
2247+ push_css(&mut aligned, "margin-left", "auto");
2248+ push_css(&mut aligned, "margin-right", "auto");
27772249 }
2778− "color" => {
2779− if let Some(v) = val {
2780− push_css(&mut css, "color", v);
2781− }
2250+ "center-y" => {
2251+ push_css(&mut aligned, "margin-top", "auto");
2252+ push_css(&mut aligned, "margin-bottom", "auto");
27822253 }
2783− "border" => {
2254+ "align-left" => push_css(&mut aligned, "margin-right", "auto"),
2255+ "align-right" => push_css(&mut aligned, "margin-left", "auto"),
2256+ "align-top" => push_css(&mut aligned, "margin-bottom", "auto"),
2257+ "align-bottom" => push_css(&mut aligned, "margin-top", "auto"),
2258+
2259+ "wrap" if lays_out_children => push_css(&mut css, "flex-wrap", "wrap"),
2260+ "wrap" => {}
2261+
2262+ // Grid
2263+ "grid-cols" | "grid-rows" if !lays_out_children => {}
2264+ "grid-cols" | "grid-rows" => {
27842265 if let Some(v) = val {
2785− let parts: Vec<&str> = v.splitn(2, ' ').collect();
2786− if parts.len() == 2 {
2787− push_css(
2788− &mut css,
2789− "border",
2790− &format!("{} solid {}", css_px(parts[0]), parts[1]),
2791− );
2266+ let property = if effective_key == "grid-cols" {
2267+ "grid-template-columns"
27922268 } else {
2793− push_css(
2794− &mut css,
2795− "border",
2796− &format!("{} solid currentColor", css_px(parts[0])),
2797− );
2269+ "grid-template-rows"
2270+ };
2271+ match v.parse::<u32>() {
2272+ Ok(n) => push_css(&mut css, property, &format!("repeat({},1fr)", n)),
2273+ Err(_) => push_css(&mut css, property, &with_px(property, v)),
27982274 }
27992275 }
28002276 }
2801− "border-top" | "border-bottom" | "border-left" | "border-right" => {
2277+ "col-span" | "row-span" => {
28022278 if let Some(v) = val {
2803− let parts: Vec<&str> = v.splitn(2, ' ').collect();
2804− if parts.len() == 2 {
2805− push_css(
2806− &mut css,
2807− effective_key,
2808− &format!("{} solid {}", css_px(parts[0]), parts[1]),
2809− );
2279+ let property = if effective_key == "col-span" {
2280+ "grid-column"
28102281 } else {
2811− push_css(
2812− &mut css,
2813− effective_key,
2814− &format!("{} solid currentColor", css_px(parts[0])),
2815− );
2816− }
2817− }
2818− }
2819− "rounded" => {
2820− if let Some(v) = val {
2821− push_css(&mut css, "border-radius", &css_px(v));
2822− }
2823− }
2824− "bold" => push_css(&mut css, "font-weight", "bold"),
2825− "italic" => push_css(&mut css, "font-style", "italic"),
2826− "underline" => push_css(&mut css, "text-decoration", "underline"),
2827− "size" => {
2828− if let Some(v) = val {
2829− push_css(&mut css, "font-size", &css_px(v));
2830− }
2831− }
2832− "font" => {
2833− if let Some(v) = val {
2834− // `font "Inter, sans-serif"` quotes a whole font stack so
2835− // its commas don't split the attribute list.
2836− let v = match v.strip_prefix('"').and_then(|v| v.strip_suffix('"')) {
2837− Some(stack) if stack.contains(',') => stack,
2838− _ => v,
2282+ "grid-row"
28392283 };
2840− push_css(&mut css, "font-family", v);
2841− }
2842− }
2843− "transition" => {
2844− if let Some(v) = val {
2845− push_css(&mut css, "transition", v);
2846− }
2847− }
2848− "cursor" => {
2849− if let Some(v) = val {
2850− push_css(&mut css, "cursor", v);
2851− }
2852− }
2853− "opacity" => {
2854− if let Some(v) = val {
2855− push_css(&mut css, "opacity", v);
2284+ push_css(&mut css, property, &format!("span {}", v));
28562285 }
28572286 }
28582287
2859− // Typography
2860− "text-align" => {
2861− if let Some(v) = val {
2862− push_css(&mut css, "text-align", v);
2863− }
2864− }
2865− "line-height" => {
2866− if let Some(v) = val {
2867− push_css(&mut css, "line-height", &css_line_height(v));
2868− }
2869− }
2870− "letter-spacing" => {
2871− if let Some(v) = val {
2872− push_css(&mut css, "letter-spacing", &css_px(v));
2873− }
2874− }
2875− "text-transform" => {
2876− if let Some(v) = val {
2877− push_css(&mut css, "text-transform", v);
2878− }
2879− }
2880− "white-space" => {
2288+ // CSS's `line-clamp` has no support yet without its
2289+ // `-webkit-` fallback, which needs a box to clamp
2290+ "line-clamp" => {
28812291 if let Some(v) = val {
2882− push_css(&mut css, "white-space", v);
2292+ push_css(&mut css, "display", "-webkit-box");
2293+ push_css(&mut css, "-webkit-line-clamp", v);
2294+ push_css(&mut css, "-webkit-box-orient", "vertical");
2295+ push_css(&mut css, "overflow", "hidden");
28832296 }
28842297 }
28852298
2886− // Overflow & positioning
2887− "overflow" => {
2299+ // Every other name is a CSS property (standard, custom,
2300+ // vendor-prefixed, or one htmlang doesn't know, which the
2301+ // parser warned about), written under its own name with the
2302+ // value as written, except for `px` after a bare number where
2303+ // the property takes a length
2304+ key if crate::vocab::is_property_name(key) => {
28882305 if let Some(v) = val {
2889− push_css(&mut css, "overflow", v);
2306+ push_css(&mut css, key, &with_px(key, v));
28902307 }
28912308 }
2892− "position" => {
2893− if let Some(v) = val {
2894− push_css(&mut css, "position", v);
2895− }
2896− }
2897− "top" => {
2898− if let Some(v) = val {
2899− push_css(&mut css, "top", &css_px(v));
2900− }
2901− }
2902− "right" => {
2903− if let Some(v) = val {
2904− push_css(&mut css, "right", &css_px(v));
2905− }
2906− }
2907− "bottom" => {
2908− if let Some(v) = val {
2909− push_css(&mut css, "bottom", &css_px(v));
2910− }
2911− }
2912− "left" => {
2913− if let Some(v) = val {
2914− push_css(&mut css, "left", &css_px(v));
2915− }
2916− }
2917− "z-index" => {
2918− if let Some(v) = val {
2919− push_css(&mut css, "z-index", v);
2920− }
2921− }
2922−
2923− // Display & visibility
2924− "display" => {
2925− if let Some(v) = val {
2926− push_css(&mut css, "display", v);
2927− }
2928− }
2929− "visibility" => {
2930− if let Some(v) = val {
2931− push_css(&mut css, "visibility", v);
2932− }
2933− }
2934− "hidden" => push_css(&mut css, "display", "none"),
2935−
2936− // Transform & filters
2937− "transform" => {
2938− if let Some(v) = val {
2939− push_css(&mut css, "transform", v);
2940− }
2941− }
2942− "backdrop-filter" => {
2943− if let Some(v) = val {
2944− push_css(&mut css, "backdrop-filter", v);
2945− }
2946− }
2947−
2948− // Effects
2949− "shadow" => {
2950− if let Some(v) = val {
2951− push_css(&mut css, "box-shadow", v);
2952− }
2953− }
2954−
2955− // Flow
2956− "wrap" => push_css(&mut css, "flex-wrap", "wrap"),
2957− "gap-x" => {
2958− if let Some(v) = val {
2959− push_css(&mut css, "column-gap", &css_px(v));
2960− }
2961− }
2962− "gap-y" => {
2963− if let Some(v) = val {
2964− push_css(&mut css, "row-gap", &css_px(v));
2965− }
2966− }
2967−
2968− // Grid
2969− "grid" => {
2970− push_css(&mut css, "display", "grid");
2971− }
2972− "grid-cols" => {
2973− if let Some(v) = val {
2974− if let Ok(n) = v.parse::<u32>() {
2975− push_css(
2976− &mut css,
2977− "grid-template-columns",
2978− &format!("repeat({},1fr)", n),
2979− );
2980− } else {
2981− push_css(&mut css, "grid-template-columns", v);
2982− }
2983− }
2984− }
2985− "grid-rows" => {
2986− if let Some(v) = val {
2987− if let Ok(n) = v.parse::<u32>() {
2988− push_css(
2989− &mut css,
2990− "grid-template-rows",
2991− &format!("repeat({},1fr)", n),
2992− );
2993− } else {
2994− push_css(&mut css, "grid-template-rows", v);
2995− }
2996− }
2997− }
2998− "col-span" => {
2999− if let Some(v) = val {
3000− push_css(&mut css, "grid-column", &format!("span {}", v));
3001− }
3002− }
3003− "row-span" => {
3004− if let Some(v) = val {
3005− push_css(&mut css, "grid-row", &format!("span {}", v));
3006− }
3007− }
3008−
3009− // Animation
3010− "animation" => {
3011− if let Some(v) = val {
3012− push_css(&mut css, "animation", v);
3013− }
3014− }
3015−
3016− // Aspect ratio
3017− "aspect-ratio" => {
3018− if let Some(v) = val {
3019− push_css(&mut css, "aspect-ratio", v);
3020− }
3021− }
3022−
3023− // CSS containment for rendering performance
3024− "contain" => {
3025− if let Some(v) = val {
3026− push_css(&mut css, "contain", v);
3027− } else {
3028− push_css(&mut css, "contain", "layout style paint");
3029− }
3030− }
3031− "content-visibility" => {
3032− if let Some(v) = val {
3033− push_css(&mut css, "content-visibility", v);
3034− } else {
3035− push_css(&mut css, "content-visibility", "auto");
3036− }
3037− }
3038−
3039− // Outline (like border but doesn't affect layout)
3040− "outline" => {
3041− if let Some(v) = val {
3042− let parts: Vec<&str> = v.splitn(2, ' ').collect();
3043− if parts.len() == 2 {
3044− push_css(
3045− &mut css,
3046− "outline",
3047− &format!("{} solid {}", css_px(parts[0]), parts[1]),
3048− );
3049− } else {
3050− push_css(
3051− &mut css,
3052− "outline",
3053− &format!("{} solid currentColor", css_px(parts[0])),
3054− );
3055− }
3056− }
3057− }
3058−
3059− // Logical properties (i18n-aware)
3060− "padding-inline" => {
3061− if let Some(v) = val {
3062− push_css(&mut css, "padding-inline", &css_px_multi(v));
3063− }
3064− }
3065− "padding-block" => {
3066− if let Some(v) = val {
3067− push_css(&mut css, "padding-block", &css_px_multi(v));
3068− }
3069− }
3070− "margin-inline" => {
3071− if let Some(v) = val {
3072− push_css(&mut css, "margin-inline", &css_px_multi(v));
3073− }
3074− }
3075− "margin-block" => {
3076− if let Some(v) = val {
3077− push_css(&mut css, "margin-block", &css_px_multi(v));
3078− }
3079− }
3080−
3081− // Logical property start/end variants
3082− "padding-inline-start"
3083− | "padding-inline-end"
3084− | "padding-block-start"
3085− | "padding-block-end"
3086− | "margin-inline-start"
3087− | "margin-inline-end"
3088− | "margin-block-start"
3089− | "margin-block-end" => {
3090− if let Some(v) = val {
3091− push_css(&mut css, effective_key, &css_px(v));
3092− }
3093− }
3094−
3095− // Logical inset
3096− "inset-inline" | "inset-block" => {
3097− if let Some(v) = val {
3098− push_css(&mut css, effective_key, &css_px_multi(v));
3099− }
3100− }
3101− "inset-inline-start" | "inset-inline-end" | "inset-block-start" | "inset-block-end" => {
3102− if let Some(v) = val {
3103− push_css(&mut css, effective_key, &css_px(v));
3104− }
3105− }
3106−
3107− // Logical border
3108− "border-inline"
3109− | "border-block"
3110− | "border-inline-start"
3111− | "border-inline-end"
3112− | "border-block-start"
3113− | "border-block-end" => {
3114− if let Some(v) = val {
3115− push_css(&mut css, effective_key, v);
3116− }
3117− }
3118−
3119− // Logical border-radius
3120− "border-start-start-radius"
3121− | "border-start-end-radius"
3122− | "border-end-start-radius"
3123− | "border-end-end-radius" => {
3124− if let Some(v) = val {
3125− push_css(&mut css, effective_key, &css_px(v));
3126− }
3127− }
3128−
3129− // Logical scroll margins & padding
3130− "scroll-margin-inline"
3131− | "scroll-margin-block"
3132− | "scroll-padding-inline"
3133− | "scroll-padding-block" => {
3134− if let Some(v) = val {
3135− push_css(&mut css, effective_key, &css_px_multi(v));
3136− }
3137− }
3138−
3139− // Logical sizing
3140− "inline-size" | "block-size" | "min-inline-size" | "max-inline-size"
3141− | "min-block-size" | "max-block-size" => {
3142− if let Some(v) = val {
3143− push_css(&mut css, effective_key, &css_px(v));
3144− }
3145− }
3146−
3147− // Scroll snap
3148− "scroll-snap-type" => {
3149− if let Some(v) = val {
3150− push_css(&mut css, "scroll-snap-type", v);
3151− }
3152− }
3153− "scroll-snap-align" => {
3154− if let Some(v) = val {
3155− push_css(&mut css, "scroll-snap-align", v);
3156− }
3157− }
3158−
3159− // Margin
3160− "margin" => {
3161− if let Some(v) = val {
3162− push_css(&mut css, "margin", &css_px_multi(v));
3163− }
3164− }
3165− "margin-x" => {
3166− if let Some(v) = val {
3167− push_css(&mut css, "margin-inline", &css_px(v));
3168− }
3169− }
3170− "margin-y" => {
3171− if let Some(v) = val {
3172− push_css(&mut css, "margin-block", &css_px(v));
3173− }
3174− }
3175−
3176− // Filter
3177− "filter" => {
3178− if let Some(v) = val {
3179− push_css(&mut css, "filter", v);
3180− }
3181− }
3182−
3183− // Object fit/position (for images)
3184− "object-fit" => {
3185− if let Some(v) = val {
3186− push_css(&mut css, "object-fit", v);
3187− }
3188− }
3189− "object-position" => {
3190− if let Some(v) = val {
3191− push_css(&mut css, "object-position", v);
3192− }
3193− }
3194−
3195− // Text shadow
3196− "text-shadow" => {
3197− if let Some(v) = val {
3198− push_css(&mut css, "text-shadow", v);
3199− }
3200− }
3201−
3202− // Text overflow
3203− "text-overflow" => {
3204− if let Some(v) = val {
3205− push_css(&mut css, "text-overflow", v);
3206− }
3207− }
3208−
3209− // Interaction
3210− "pointer-events" => {
3211− if let Some(v) = val {
3212− push_css(&mut css, "pointer-events", v);
3213− }
3214− }
3215− "user-select" => {
3216− if let Some(v) = val {
3217− push_css(&mut css, "user-select", v);
3218− }
3219− }
3220−
3221− // Flexbox/grid alignment
3222− "justify-content" => {
3223− if let Some(v) = val {
3224− push_css(&mut css, "justify-content", v);
3225− }
3226− }
3227− "align-items" => {
3228− if let Some(v) = val {
3229− push_css(&mut css, "align-items", v);
3230− }
3231− }
3232−
3233− // Flex item order
3234− "order" => {
3235− if let Some(v) = val {
3236− push_css(&mut css, "order", v);
3237− }
3238− }
3239−
3240− // Background extras
3241− "background-size" => {
3242− if let Some(v) = val {
3243− push_css(&mut css, "background-size", v);
3244− }
3245− }
3246− "background-position" => {
3247− if let Some(v) = val {
3248− push_css(&mut css, "background-position", v);
3249− }
3250− }
3251− "background-repeat" => {
3252− if let Some(v) = val {
3253− push_css(&mut css, "background-repeat", v);
3254− }
3255− }
3256−
3257− // Text wrapping
3258− "word-break" => {
3259− if let Some(v) = val {
3260− push_css(&mut css, "word-break", v);
3261− }
3262− }
3263− "overflow-wrap" => {
3264− if let Some(v) = val {
3265− push_css(&mut css, "overflow-wrap", v);
3266− }
3267− }
3268−
3269− // Container queries
3270− "container" => {
3271− push_css(&mut css, "container-type", "inline-size");
3272− }
3273− "container-name" => {
3274− if let Some(v) = val {
3275− push_css(&mut css, "container-name", v);
3276− }
3277− }
3278− "container-type" => {
3279− if let Some(v) = val {
3280− push_css(&mut css, "container-type", v);
3281− }
3282− }
3283−
3284− // Overflow axis
3285− "overflow-x" => {
3286− if let Some(v) = val {
3287− push_css(&mut css, "overflow-x", v);
3288− }
3289− }
3290− "overflow-y" => {
3291− if let Some(v) = val {
3292− push_css(&mut css, "overflow-y", v);
3293− }
3294− }
3295−
3296− // Inset (shorthand for top/right/bottom/left)
3297− "inset" => {
3298− if let Some(v) = val {
3299− push_css(&mut css, "inset", &css_px(v));
3300− }
3301− }
3302−
3303− // Accent & caret colors
3304− "accent-color" => {
3305− if let Some(v) = val {
3306− push_css(&mut css, "accent-color", v);
3307− }
3308− }
3309− "caret-color" => {
3310− if let Some(v) = val {
3311− push_css(&mut css, "caret-color", v);
3312− }
3313− }
3314−
3315− // Color scheme & appearance
3316− "color-scheme" => {
3317− if let Some(v) = val {
3318− push_css(&mut css, "color-scheme", v);
3319− }
3320− }
3321− "appearance" => {
3322− if let Some(v) = val {
3323− push_css(&mut css, "appearance", v);
3324− }
3325− }
3326−
3327− // List style
3328− "list-style" => {
3329− if let Some(v) = val {
3330− push_css(&mut css, "list-style", v);
3331− }
3332− }
3333−
3334− // Table
3335− "border-collapse" => {
3336− if let Some(v) = val {
3337− push_css(&mut css, "border-collapse", v);
3338− }
3339− }
3340− "border-spacing" => {
3341− if let Some(v) = val {
3342− push_css(&mut css, "border-spacing", &css_px(v));
3343− }
3344− }
3345−
3346− // Text decoration
3347− "text-decoration" => {
3348− if let Some(v) = val {
3349− push_css(&mut css, "text-decoration", v);
3350− }
3351− }
3352− "text-decoration-color" => {
3353− if let Some(v) = val {
3354− push_css(&mut css, "text-decoration-color", v);
3355− }
3356− }
3357− "text-decoration-thickness" => {
3358− if let Some(v) = val {
3359− push_css(&mut css, "text-decoration-thickness", &css_px(v));
3360− }
3361− }
3362− "text-decoration-style" => {
3363− if let Some(v) = val {
3364− push_css(&mut css, "text-decoration-style", v);
3365− }
3366− }
3367− "text-underline-offset" => {
3368− if let Some(v) = val {
3369− push_css(&mut css, "text-underline-offset", &css_px(v));
3370− }
3371− }
3372−
3373− // Multi-column
3374− "column-width" => {
3375− if let Some(v) = val {
3376− push_css(&mut css, "column-width", &css_px(v));
3377− }
3378− }
3379− "column-rule" => {
3380− if let Some(v) = val {
3381− push_css(&mut css, "column-rule", v);
3382− }
3383− }
3384−
3385− // Place items/self
3386− "place-items" => {
3387− if let Some(v) = val {
3388− push_css(&mut css, "place-items", v);
3389− }
3390− }
3391− "place-self" => {
3392− if let Some(v) = val {
3393− push_css(&mut css, "place-self", v);
3394− }
3395− }
3396−
3397− // Scroll behavior
3398− "scroll-behavior" => {
3399− if let Some(v) = val {
3400− push_css(&mut css, "scroll-behavior", v);
3401− }
3402− }
3403−
3404− // Resize
3405− "resize" => {
3406− if let Some(v) = val {
3407− push_css(&mut css, "resize", v);
3408− }
3409− }
3410−
3411− // New CSS properties
3412− "clip-path" => {
3413− if let Some(v) = val {
3414− push_css(&mut css, "clip-path", v);
3415− }
3416− }
3417− "mix-blend-mode" => {
3418− if let Some(v) = val {
3419− push_css(&mut css, "mix-blend-mode", v);
3420− }
3421− }
3422− "background-blend-mode" => {
3423− if let Some(v) = val {
3424− push_css(&mut css, "background-blend-mode", v);
3425− }
3426− }
3427− "writing-mode" => {
3428− if let Some(v) = val {
3429− push_css(&mut css, "writing-mode", v);
3430− }
3431− }
3432− "column-count" => {
3433− if let Some(v) = val {
3434− push_css(&mut css, "column-count", v);
3435− }
3436− }
3437− "column-gap" => {
3438− if let Some(v) = val {
3439− push_css(&mut css, "column-gap", &css_px(v));
3440− }
3441− }
3442− "text-indent" => {
3443− if let Some(v) = val {
3444− push_css(&mut css, "text-indent", &css_px(v));
3445− }
3446− }
3447− "hyphens" => {
3448− if let Some(v) = val {
3449− push_css(&mut css, "hyphens", v);
3450− }
3451− }
3452− "flex-grow" => {
3453− if let Some(v) = val {
3454− push_css(&mut css, "flex-grow", v);
3455− }
3456− }
3457− "flex-shrink" => {
3458− if let Some(v) = val {
3459− push_css(&mut css, "flex-shrink", v);
3460− }
3461− }
3462− "flex-basis" => {
3463− if let Some(v) = val {
3464− push_css(&mut css, "flex-basis", &css_px(v));
3465− }
3466− }
3467− "isolation" => {
3468− if let Some(v) = val {
3469− push_css(&mut css, "isolation", v);
3470− }
3471− }
3472− "place-content" => {
3473− if let Some(v) = val {
3474− push_css(&mut css, "place-content", v);
3475− }
3476− }
3477− "background-image" => {
3478− if let Some(v) = val {
3479− push_css(&mut css, "background-image", v);
3480− }
3481− }
3482− "font-weight" => {
3483− if let Some(v) = val {
3484− push_css(&mut css, "font-weight", v);
3485− }
3486− }
3487− "font-style" => {
3488− if let Some(v) = val {
3489− push_css(&mut css, "font-style", v);
3490− }
3491− }
3492− "text-wrap" => {
3493− if let Some(v) = val {
3494− push_css(&mut css, "text-wrap", v);
3495− }
3496− }
3497− "will-change" => {
3498− if let Some(v) = val {
3499− push_css(&mut css, "will-change", v);
3500− }
3501− }
3502− "touch-action" => {
3503− if let Some(v) = val {
3504− push_css(&mut css, "touch-action", v);
3505− }
3506− }
3507− "vertical-align" => {
3508− if let Some(v) = val {
3509− push_css(&mut css, "vertical-align", v);
3510− }
3511− }
3512− "scroll-margin" => {
3513− if let Some(v) = val {
3514− push_css(&mut css, "scroll-margin", &css_px(v));
3515− }
3516− }
3517− "scroll-margin-top"
3518− | "scroll-margin-bottom"
3519− | "scroll-margin-left"
3520− | "scroll-margin-right" => {
3521− if let Some(v) = val {
3522− push_css(&mut css, effective_key, &css_px(v));
3523− }
3524− }
3525− "scroll-padding" => {
3526− if let Some(v) = val {
3527− push_css(&mut css, "scroll-padding", &css_px(v));
3528− }
3529− }
3530− "scroll-padding-top"
3531− | "scroll-padding-bottom"
3532− | "scroll-padding-left"
3533− | "scroll-padding-right" => {
3534− if let Some(v) = val {
3535− push_css(&mut css, effective_key, &css_px(v));
3536− }
3537− }
3538− "direction" => {
3539− if let Some(v) = val {
3540− push_css(&mut css, "direction", v);
3541− }
3542− }
3543−
3544− "content" => {
3545− if let Some(v) = val {
3546− // Wrap in quotes if not already quoted and not a CSS keyword
3547− if v.starts_with('"')
3548− || v.starts_with('\'')
3549− || v == "none"
3550− || v == "normal"
3551− || v.starts_with("attr(")
3552− || v.starts_with("counter(")
3553− {
3554− push_css(&mut css, "content", v);
3555− } else {
3556− push_css(&mut css, "content", &format!("\"{}\"", v));
3557− }
3558− }
3559− }
3560−
3561− // --- CSS Shorthands ---
3562− "truncate" => {
3563− push_css(&mut css, "overflow", "hidden");
3564− push_css(&mut css, "text-overflow", "ellipsis");
3565− push_css(&mut css, "white-space", "nowrap");
3566− }
3567− "line-clamp" => {
3568− if let Some(v) = val {
3569− push_css(&mut css, "display", "-webkit-box");
3570− push_css(&mut css, "-webkit-line-clamp", v);
3571− push_css(&mut css, "-webkit-box-orient", "vertical");
3572− push_css(&mut css, "overflow", "hidden");
3573− }
3574− }
3575− "blur" => {
3576− if let Some(v) = val {
3577− push_css(&mut css, "filter", &format!("blur({})", css_px(v)));
3578− }
3579− }
3580− "backdrop-blur" => {
3581− if let Some(v) = val {
3582− push_css(&mut css, "backdrop-filter", &format!("blur({})", css_px(v)));
3583− }
3584− }
3585− "no-scrollbar" => {
3586− push_css(&mut css, "scrollbar-width", "none");
3587− push_css(&mut css, "-ms-overflow-style", "none");
3588− }
3589− "skeleton" => {
3590− push_css(
3591− &mut css,
3592− "background",
3593− "linear-gradient(90deg,#e5e7eb 25%,#f3f4f6 50%,#e5e7eb 75%)",
3594− );
3595− push_css(&mut css, "background-size", "200% 100%");
3596− push_css(
3597− &mut css,
3598− "animation",
3599− "hl-skeleton 1.5s ease-in-out infinite",
3600− );
3601− }
3602− "gradient" => {
3603− if let Some(v) = val {
3604− // Parse: "from to [angle]" or "color1 color2 [angle]"
3605− let parts: Vec<&str> = v.split_whitespace().collect();
3606− let bg = if parts.len() >= 3
3607− && (parts[2].ends_with("deg")
3608− || parts[2].ends_with("turn")
3609− || parts[2].ends_with("rad"))
3610− {
3611− format!("linear-gradient({},{},{})", parts[2], parts[0], parts[1])
3612− } else if parts.len() >= 2 {
3613− format!("linear-gradient({},{})", parts[0], parts[1])
3614− } else {
3615− format!("linear-gradient({},transparent)", parts[0])
3616− };
3617− push_css(&mut css, "background", &bg);
3618− }
3619− }
3620−
3621− // Grid areas
3622− "grid-template-areas" => {
3623− if let Some(v) = val {
3624− push_css(&mut css, "grid-template-areas", v);
3625− }
3626− }
3627− "grid-area" => {
3628− if let Some(v) = val {
3629− push_css(&mut css, "grid-area", v);
3630− }
3631− }
3632−
3633− // View transitions
3634− "view-transition-name" => {
3635− if let Some(v) = val {
3636− push_css(&mut css, "view-transition-name", v);
3637− }
3638− }
3639−
3640− // Animate shorthand (alias for animation)
3641− "animate" => {
3642− if let Some(v) = val {
3643− push_css(&mut css, "animation", v);
3644− }
3645− }
3646−
3647− // CSS subgrid
3648− "grid-template-columns" => {
3649− if let Some(v) = val {
3650− push_css(&mut css, "grid-template-columns", v);
3651− }
3652− }
3653− "grid-template-rows" => {
3654− if let Some(v) = val {
3655− push_css(&mut css, "grid-template-rows", v);
3656− }
3657− }
3658−
3659− // Scroll-driven animations
3660− "animation-timeline" => {
3661− if let Some(v) = val {
3662− push_css(&mut css, "animation-timeline", v);
3663− }
3664− }
3665− "animation-range" => {
3666− if let Some(v) = val {
3667− push_css(&mut css, "animation-range", v);
3668− }
3669− }
3670− "view-timeline-name" => {
3671− if let Some(v) = val {
3672− push_css(&mut css, "view-timeline-name", v);
3673− }
3674− }
3675− "view-timeline-axis" => {
3676− if let Some(v) = val {
3677− push_css(&mut css, "view-timeline-axis", v);
3678− }
3679− }
3680− "scroll-timeline-name" => {
3681− if let Some(v) = val {
3682− push_css(&mut css, "scroll-timeline-name", v);
3683− }
3684− }
3685− "scroll-timeline-axis" => {
3686− if let Some(v) = val {
3687− push_css(&mut css, "scroll-timeline-axis", v);
3688− }
3689− }
3690−
3691− // Anchor positioning
3692− "anchor-name" => {
3693− if let Some(v) = val {
3694− push_css(&mut css, "anchor-name", v);
3695− }
3696− }
3697− "position-anchor" => {
3698− if let Some(v) = val {
3699− push_css(&mut css, "position-anchor", v);
3700− }
3701− }
3702− "position-area" => {
3703− if let Some(v) = val {
3704− push_css(&mut css, "position-area", v);
3705− }
3706− }
3707− "inset-area" => {
3708− // Legacy alias for position-area
3709− if let Some(v) = val {
3710− push_css(&mut css, "position-area", v);
3711− }
3712− }
3713−
3714− // initial-letter (drop caps)
3715− "initial-letter" => {
3716− if let Some(v) = val {
3717− push_css(&mut css, "initial-letter", v);
3718− }
3719− }
3720−
3721− // Critical CSS hint — not CSS, handled elsewhere
3722− "critical" => {}
3723−
3724− // Identity and HTML passthrough — not CSS
3725− "id" | "class" => {}
3726− "type" | "placeholder" | "name" | "value" | "disabled" | "required" | "checked"
3727− | "for" | "action" | "method" | "autocomplete" | "min" | "max" | "step" | "pattern"
3728− | "maxlength" | "rows" | "cols" | "multiple" | "alt" | "role" | "tabindex"
3729− | "title" | "controls" | "autoplay" | "loop" | "muted" | "playsinline" | "poster"
3730− | "preload" | "loading" | "decoding" | "ordered" | "src" | "open" | "novalidate"
3731− | "low" | "high" | "optimum" | "colspan" | "rowspan" | "scope" | "inline"
3732− | "responsive" | "datetime" | "media" | "sizes" | "srcset" | "cite" | "list"
3733− | "sandbox" | "allow" | "allowfullscreen" | "referrerpolicy" | "formaction"
3734− | "formmethod" | "formtarget" | "target" | "autofocus" => {}
37352309
37362310 _ => {}
37372311 }
37382312 }
37392313
2314+ css.push_str(&aligned);
37402315 css
37412316}
37422317
@@ -3747,262 +2322,10 @@ fn push_css(css: &mut String, prop: &str, value: &str) {
37472322 css.push(';');
37482323}
37492324
3750−/// Known CSS units — if a value ends with one, skip appending `px`.
3751−/// Format a length value: a bare number gets `px` appended; anything else
3752−/// (values with units, keywords like `auto`, functions like `calc(...)`) is
3753−/// passed through unchanged.
3754−fn css_px(value: &str) -> String {
3755− let v = value.trim();
3756− if v == "0" {
3757− return "0".to_string();
3758− }
3759− let is_bare_number = !v.is_empty()
3760− && v.bytes().all(|b| b.is_ascii_digit() || matches!(b, b'.' | b'-' | b'+'))
3761− && v.parse::<f64>().is_ok();
3762− if is_bare_number {
3763− format!("{}px", v)
3764− } else {
3765− v.to_string()
3766− }
3767−}
3768−
3769−/// Rewrite literal values that match a declared CSS custom property (from
3770−/// `@theme` or `@let --name value`) to `var(--name)` references. Matches are
3771−/// anchored to CSS value boundaries so e.g. `#3b82f6` inside a longer hex or
3772−/// inside an identifier is not replaced. The `:root` block is emitted before
3773−/// this call runs, so its declarations are not affected.
3774−fn substitute_css_vars(css: &str, vars: &[(String, String)]) -> String {
3775− if css.is_empty() || vars.is_empty() {
3776− return css.to_string();
3777− }
3778− // Prefer longer values first so that if two vars share a prefix, the
3779− // longer (more specific) match wins.
3780− let mut pairs: Vec<(&str, String)> = vars
3781− .iter()
3782− .filter(|(name, value)| name.starts_with("--") && !value.is_empty())
3783− .map(|(name, value)| (value.as_str(), format!("var({})", name)))
3784− .collect();
3785− pairs.sort_by_key(|(v, _)| std::cmp::Reverse(v.len()));
3786− if pairs.is_empty() {
3787− return css.to_string();
3788− }
3789−
3790− let is_boundary_before = |b: Option<u8>| match b {
3791− None => true,
3792− Some(c) => matches!(c, b':' | b' ' | b',' | b'(' | b';' | b'{' | b'\n' | b'\t'),
3793− };
3794− let is_boundary_after = |b: Option<u8>| match b {
3795− None => true,
3796− Some(c) => matches!(c, b';' | b'}' | b',' | b' ' | b')' | b'\n' | b'\t'),
3797− };
3798−
3799− let bytes = css.as_bytes();
3800− let mut out = String::with_capacity(css.len());
3801− let mut i = 0;
3802− let mut prev: Option<u8> = None;
3803− // Only declaration values are rewritten — never selectors or at-rule
3804− // preludes such as `@media (min-width:768px)`. `blocks` records, for
3805− // each open `{`, whether it holds declarations (a style rule) or nested
3806− // rules (an at-rule like `@media` / `@layer`).
3807− let mut blocks: Vec<bool> = Vec::new();
3808− let mut prelude_start = 0;
3809− let mut in_value = false;
3810− while i < bytes.len() {
3811− match bytes[i] {
3812− b'{' => {
3813− let prelude = css[prelude_start..i].trim_start();
3814− blocks.push(!prelude.starts_with('@'));
3815− in_value = false;
3816− prelude_start = i + 1;
3817− }
3818− b'}' => {
3819− blocks.pop();
3820− in_value = false;
3821− prelude_start = i + 1;
3822− }
3823− b';' => {
3824− in_value = false;
3825− prelude_start = i + 1;
3826− }
3827− b':' if blocks.last() == Some(&true) => in_value = true,
3828− _ => {}
3829− }
3830− if in_value && is_boundary_before(prev) {
3831− let mut matched = false;
3832− for (val, repl) in &pairs {
3833− let vb = val.as_bytes();
3834− if i + vb.len() <= bytes.len() && &bytes[i..i + vb.len()] == vb {
3835− let next = bytes.get(i + vb.len()).copied();
3836− if is_boundary_after(next) {
3837− out.push_str(repl);
3838− prev = repl.as_bytes().last().copied();
3839− i += vb.len();
3840− matched = true;
3841− break;
3842− }
3843− }
3844− }
3845− if matched {
3846− continue;
3847− }
3848− }
3849− // Advance by one UTF-8 code point.
3850− let start = i;
3851− i += 1;
3852− while i < bytes.len() && (bytes[i] & 0xC0) == 0x80 {
3853− i += 1;
3854− }
3855− out.push_str(&css[start..i]);
3856− prev = bytes.get(i - 1).copied();
3857− }
3858− out
3859−}
3860−
3861−/// Scan generated CSS for literal property values that repeat often enough
3862−/// that substituting them with an auto-named custom property would reduce
3863−/// total byte count. Returns the rewritten CSS and any new vars that should
3864−/// be appended to `:root`.
3865−///
3866−/// The algorithm only promotes a value if it strictly saves bytes after
3867−/// accounting for the `--xN:value;` declaration overhead plus the
3868−/// `var(--xN)` reference cost at each call site. Values that are already
3869−/// `var(...)` references or contain `var(` calls are skipped so we never
3870−/// nest references. Names avoid collisions with `existing_vars`.
3871−fn auto_extract_repeats(
3872− css: &str,
3873− existing_vars: &[(String, String)],
3874−) -> (String, Vec<(String, String)>) {
3875− if css.is_empty() {
3876− return (css.to_string(), Vec::new());
3877− }
3878− // Count occurrences of each distinct property value (the text between
3879− // `:` and the next `;` or `}` at the top level of a declaration block,
3880− // ignoring balanced parentheses so that e.g. `rgba(...)` stays intact).
3881− let bytes = css.as_bytes();
3882− let mut counts: HashMap<String, usize> = HashMap::new();
3883− let mut depth: i32 = 0;
3884− let mut i = 0;
3885− while i < bytes.len() {
3886− match bytes[i] {
3887− b'{' => {
3888− depth += 1;
3889− i += 1;
3890− continue;
3891− }
3892− b'}' => {
3893− if depth > 0 {
3894− depth -= 1;
3895− }
3896− i += 1;
3897− continue;
3898− }
3899− _ => {}
3900− }
3901− if depth > 0 && bytes[i] == b':' {
3902− // Skip past `:` then walk to the terminator.
3903− let start = i + 1;
3904− let mut end = start;
3905− let mut pdepth = 0i32;
3906− while end < bytes.len() {
3907− match bytes[end] {
3908− b'(' => pdepth += 1,
3909− b')' if pdepth > 0 => pdepth -= 1,
3910− b';' | b'}' if pdepth == 0 => break,
3911− b'{' if pdepth == 0 => break,
3912− _ => {}
3913− }
3914− end += 1;
3915− }
3916− let val = css[start..end].trim();
3917− if !val.is_empty() && !val.starts_with("var(") && !val.contains("var(") {
3918− *counts.entry(val.to_string()).or_default() += 1;
3919− }
3920− i = end;
3921− continue;
3922− }
3923− i += 1;
3924− }
3925−
3926− // Decide which values are worth extracting. A value of length L appearing
3927− // N times costs N*L bytes inline; promoting it costs (L + 6) for the
3928− // `--hK:V;` declaration plus N * ref_len for the call sites. We estimate
3929− // ref_len optimistically as `var(--h0)` (9 bytes) and fall back to 10 for
3930− // two-digit indices, which only affects very large extraction counts.
3931− let existing: std::collections::HashSet<&str> =
3932− existing_vars.iter().map(|(n, _)| n.as_str()).collect();
3933− let mut candidates: Vec<(String, usize)> =
3934− counts.into_iter().filter(|(_, n)| *n >= 2).collect();
3935− // Stable, deterministic ordering — longest values first, tiebreak by text.
3936− candidates.sort_by(|a, b| b.0.len().cmp(&a.0.len()).then_with(|| a.0.cmp(&b.0)));
3937−
3938− let mut extracted: Vec<(String, String)> = Vec::new();
3939− let mut next_idx: usize = 0;
3940− for (value, n) in candidates {
3941− let l = value.len();
3942− // Allocate the next unused `--hN` name.
3943− let (name, ref_len) = loop {
3944− let candidate = format!("--h{}", next_idx);
3945− next_idx += 1;
3946− let rl = candidate.len() + 6; // `var(` + name + `)`
3947− if !existing.contains(candidate.as_str())
3948− && !extracted.iter().any(|(n, _)| *n == candidate)
3949− {
3950− break (candidate, rl);
3951− }
3952− };
3953− // Skip if promotion would not strictly reduce byte count.
3954− // Before: n * l bytes. After: (l + name.len() + 2) for the :root
3955− // declaration (`<name>:<value>;`) plus n * ref_len for the sites.
3956− let decl_overhead = l + name.len() + 2;
3957− let before = n * l;
3958− let after = decl_overhead + n * ref_len;
3959− if after < before {
3960− extracted.push((name, value));
3961− } else {
3962− // Rewind the index so the next value can reuse this slot.
3963− next_idx -= 1;
3964− }
3965− }
3966−
3967− if extracted.is_empty() {
3968− return (css.to_string(), Vec::new());
3969− }
3970− let new_css = substitute_css_vars(css, &extracted);
3971− (new_css, extracted)
3972−}
3973−
3974−/// Format a `line-height` value. CSS accepts either a unitless multiplier
3975−/// (e.g. `1.5`) or a length (e.g. `24px`). Plain integers in htmlang source
3976−/// are ambiguous: `[line-height 24]` was historically emitted as `24` (which
3977−/// CSS interprets as 24× font-size — almost never what anyone wants). Treat
3978−/// integers ≥ 2 as pixel lengths; anything with a decimal, an existing unit,
3979−/// or the value `0`/`1` passes through unchanged.
3980−fn css_line_height(value: &str) -> String {
3981− let v = value.trim();
3982− if v == "0" || v == "1" {
3983− return v.to_string();
3984− }
3985− // Plain integer — treat as pixel length. Decimals, units, keywords and
3986− // functions pass through.
3987− if !v.is_empty() && v.chars().all(|c| c.is_ascii_digit()) {
3988− return format!("{}px", v);
3989− }
3990− v.to_string()
3991−}
3992−
3993−/// Format multiple space-separated values, each getting px if needed.
3994−fn css_px_multi(value: &str) -> String {
3995− value
3996− .split_whitespace()
3997− .map(css_px)
3998− .collect::<Vec<_>>()
3999− .join(" ")
4000−}
4001−
40022325fn extract_id_class(attrs: &[Attribute]) -> (Option<String>, Option<String>) {
40032326 let mut id = None;
40042327 let mut class = None;
4005− for attr in attrs {
2328+ for attr in attrs.iter().filter(|a| a.html) {
40062329 match attr.key.as_str() {
40072330 "id" => id = attr.value.clone(),
40082331 "class" => class = attr.value.clone(),
@@ -4012,153 +2335,6 @@ fn extract_id_class(attrs: &[Attribute]) -> (Option<String>, Option<String>) {
40122335 (id, class)
40132336}
40142337
4015−/// Read image dimensions from a local file by parsing the header bytes.
4016−/// Supports PNG, JPEG, GIF, WebP, AVIF, and SVG.
4017−fn read_image_dimensions(path: &str) -> Option<(u32, u32)> {
4018− // SVG: parse as text for viewBox/width/height attributes
4019− if path.ends_with(".svg") || path.ends_with(".SVG") {
4020− let text = std::fs::read_to_string(path).ok()?;
4021− return read_svg_dimensions(&text);
4022− }
4023−
4024− let data = std::fs::read(path).ok()?;
4025− if data.len() < 12 {
4026− return None;
4027− }
4028−
4029− // PNG: 8-byte signature, then IHDR chunk with width/height at bytes 16-23
4030− if data.len() >= 24 && data.starts_with(b"\x89PNG\r\n\x1a\n") {
4031− let w = u32::from_be_bytes([data[16], data[17], data[18], data[19]]);
4032− let h = u32::from_be_bytes([data[20], data[21], data[22], data[23]]);
4033− return Some((w, h));
4034− }
4035−
4036− // GIF: "GIF87a" or "GIF89a", width/height at bytes 6-9 (little-endian)
4037− if data.starts_with(b"GIF87a") || data.starts_with(b"GIF89a") {
4038− let w = u16::from_le_bytes([data[6], data[7]]) as u32;
4039− let h = u16::from_le_bytes([data[8], data[9]]) as u32;
4040− return Some((w, h));
4041− }
4042−
4043− // JPEG: scan for SOF0/SOF2 marker (0xFF 0xC0 or 0xFF 0xC2)
4044− if data.starts_with(b"\xff\xd8") {
4045− let mut i = 2;
4046− while i + 9 < data.len() {
4047− if data[i] != 0xFF {
4048− i += 1;
4049− continue;
4050− }
4051− let marker = data[i + 1];
4052− if marker == 0xC0 || marker == 0xC2 {
4053− let h = u16::from_be_bytes([data[i + 5], data[i + 6]]) as u32;
4054− let w = u16::from_be_bytes([data[i + 7], data[i + 8]]) as u32;
4055− return Some((w, h));
4056− }
4057− if i + 3 < data.len() {
4058− let len = u16::from_be_bytes([data[i + 2], data[i + 3]]) as usize;
4059− i += 2 + len;
4060− } else {
4061− break;
4062− }
4063− }
4064− }
4065−
4066− // WebP: "RIFF" ... "WEBP", VP8 header at byte 20
4067− if data.len() >= 30 && &data[..4] == b"RIFF" && &data[8..12] == b"WEBP" {
4068− if &data[12..16] == b"VP8 " && data.len() >= 30 {
4069− let w = u16::from_le_bytes([data[26], data[27]]) as u32 & 0x3FFF;
4070− let h = u16::from_le_bytes([data[28], data[29]]) as u32 & 0x3FFF;
4071− return Some((w, h));
4072− }
4073− if &data[12..16] == b"VP8L" && data.len() >= 25 && data[21] == 0x2F {
4074− let bits = u32::from_le_bytes([data[22], data[23], data[24], data[25]]);
4075− let w = (bits & 0x3FFF) + 1;
4076− let h = ((bits >> 14) & 0x3FFF) + 1;
4077− return Some((w, h));
4078− }
4079− }
4080−
4081− // AVIF: ISOBMFF container with "ftyp" box containing "avif"/"avis" brand,
4082− // then "ispe" box with width/height
4083− if data.len() >= 12 && &data[4..8] == b"ftyp" {
4084− let brand = &data[8..12];
4085− if brand == b"avif" || brand == b"avis" || brand == b"mif1" {
4086− return read_avif_dimensions(&data);
4087− }
4088− }
4089−
4090− None
4091−}
4092−
4093−/// Parse SVG viewBox or width/height attributes to get dimensions.
4094−fn read_svg_dimensions(text: &str) -> Option<(u32, u32)> {
4095− // Try viewBox first: viewBox="minX minY width height"
4096− if let Some(vb_start) = text.find("viewBox=\"") {
4097− let rest = &text[vb_start + 9..];
4098− if let Some(end) = rest.find('"') {
4099− let parts: Vec<&str> = rest[..end].split_whitespace().collect();
4100− if parts.len() == 4
4101− && let (Ok(w), Ok(h)) = (parts[2].parse::<f64>(), parts[3].parse::<f64>())
4102− && w > 0.0
4103− && h > 0.0
4104− {
4105− return Some((w.round() as u32, h.round() as u32));
4106− }
4107− }
4108− }
4109− // Fall back to width/height attributes on <svg>
4110− let svg_tag = text.find("<svg")?;
4111− let tag_end = text[svg_tag..].find('>')? + svg_tag;
4112− let tag = &text[svg_tag..tag_end];
4113− let w = extract_svg_attr(tag, "width")?;
4114− let h = extract_svg_attr(tag, "height")?;
4115− Some((w, h))
4116−}
4117−
4118−fn extract_svg_attr(tag: &str, attr: &str) -> Option<u32> {
4119− let needle = format!("{}=\"", attr);
4120− let start = tag.find(&needle)? + needle.len();
4121− let rest = &tag[start..];
4122− let end = rest.find('"')?;
4123− let val = rest[..end].trim_end_matches("px");
4124− val.parse::<f64>().ok().map(|v| v.round() as u32)
4125−}
4126−
4127−/// Parse AVIF (ISOBMFF) container to find ispe box with image dimensions.
4128−fn read_avif_dimensions(data: &[u8]) -> Option<(u32, u32)> {
4129− // Walk ISOBMFF boxes looking for "ispe" (image spatial extents)
4130− let mut i = 0;
4131− while i + 8 <= data.len() {
4132− let box_size =
4133− u32::from_be_bytes([data[i], data[i + 1], data[i + 2], data[i + 3]]) as usize;
4134− let box_type = &data[i + 4..i + 8];
4135− if box_size < 8 {
4136− break;
4137− }
4138− let box_end = (i + box_size).min(data.len());
4139− // ispe box: 4 bytes version/flags + 4 bytes width + 4 bytes height
4140− if box_type == b"ispe" && box_end >= i + 20 {
4141− let w = u32::from_be_bytes([data[i + 12], data[i + 13], data[i + 14], data[i + 15]]);
4142− let h = u32::from_be_bytes([data[i + 16], data[i + 17], data[i + 18], data[i + 19]]);
4143− return Some((w, h));
4144− }
4145− // Recurse into container boxes (meta, iprp, ipco)
4146− if matches!(
4147− box_type,
4148− b"meta" | b"iprp" | b"ipco" | b"moov" | b"trak" | b"mdia"
4149− ) {
4150− let header_size = if box_type == b"meta" { 12 } else { 8 };
4151− if i + header_size < box_end
4152− && let Some(dims) = read_avif_dimensions(&data[i + header_size..box_end])
4153− {
4154− return Some(dims);
4155− }
4156− }
4157− i = box_end;
4158− }
4159− None
4160−}
4161−
41622338fn html_escape(s: &str) -> String {
41632339 s.replace('&', "&")
41642340 .replace('<', "<")
@@ -4274,49 +2450,30 @@ fn vlq_encode(value: i64, out: &mut String) {
42742450 }
42752451}
42762452
4277−/// Check if a specific element kind exists anywhere in the node tree.
4278−fn has_element_kind(nodes: &[Node], target: &ElementKind) -> bool {
4279− for node in nodes {
4280− if let Node::Element(elem) = node {
4281− if elem.kind == *target {
4282− return true;
4283− }
4284− if has_element_kind(&elem.children, target) {
4285− return true;
4286− }
4287− }
4288− }
4289− false
4290−}
4291−
4292−/// Collect unique external domains from generated HTML for DNS prefetch hints.
4293−fn collect_dns_prefetch(html: &str, dev: bool) -> String {
4294− let mut domains = Vec::new();
4295− let mut rest = html;
4296− while let Some(pos) = rest.find("https://") {
4297− let start = pos + 8; // skip "https://"
4298− rest = &rest[start..];
4299− let end = rest
4300− .find(['/', '"', '\'', ' ', '>', ')'])
4301− .unwrap_or(rest.len());
4302− let domain = &rest[..end];
4303− if !domain.is_empty() && domain.contains('.') && !domains.contains(&domain.to_string()) {
4304− domains.push(domain.to_string());
4305− }
4306− }
4307− let mut out = String::new();
4308− for domain in &domains {
4309− if dev {
4310− out.push_str(&format!(
4311− "<link rel=\"dns-prefetch\" href=\"//{}\">\n",
4312− domain
4313− ));
4314− } else {
4315− out.push_str(&format!(
4316− "<link rel=\"dns-prefetch\" href=\"//{}\">",
4317− domain
4318− ));
4319− }
2453+#[cfg(test)]
2454+mod tests {
2455+ use super::*;
2456+
2457+ #[test]
2458+ fn a_name_is_a_stable_hash_of_the_style() {
2459+ // The same in every build and on every platform
2460+ assert_eq!(stable_hash(""), 0xf52a_15e9_a9b5_e89b);
2461+ assert_eq!(hash_digits(35, 3), "z00");
2462+ assert_eq!(hash_digits(u64::MAX, 13), "fsgs46211e5w3");
2463+ }
2464+
2465+ #[test]
2466+ fn a_name_taken_in_the_file_takes_more_digits() {
2467+ // These two styles' hashes end in the same 7 digits
2468+ let mut styles = StyleCollector::new();
2469+ let first = styles.get_class("width:129555px;".into(), Vec::new(), String::new());
2470+ let second = styles.get_class("width:170577px;".into(), Vec::new(), String::new());
2471+ let (first, second) = (first.unwrap(), second.unwrap());
2472+ assert_eq!(first.len(), 3 + CLASS_DIGITS, "{first}");
2473+ assert_eq!(second.len(), 3 + CLASS_DIGITS + 1, "{second}");
2474+ assert!(second.starts_with(&first), "{first} {second}");
2475+ // The same style gets the name it got before
2476+ let again = styles.get_class("width:170577px;".into(), Vec::new(), String::new());
2477+ assert_eq!(again.as_deref(), Some(second.as_str()));
43202478 }
4321− out
43222479}