@@ -1,8 +1,7 @@
11use std::collections::HashMap;
2−use std::hash::Hash;
2+use std::hash::{Hash, Hasher};
33
44use crate::ast::*;
5−use crate::vocab::with_px;
65
76// ---------------------------------------------------------------------------
87// Style collector: deduplicates CSS and assigns class names
@@ -17,315 +16,56 @@ const BREAKPOINTS: &[(&str, &str)] = &[
1716 ("2xl", "1536px"),
1817];
1918
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− }
217− }
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)
272− }
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
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);
32+ }
33+ let mut tail = Vec::with_capacity(len - 1);
34+ for _ in 1..len {
35+ tail.push(REST[n % 36]);
36+ n /= 36;
37+ }
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
29642}
29743
29844struct StyleEntry {
29945 class_name: 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,
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)>,
31461}
31562
31663struct StyleCollector {
31764 entries: Vec<StyleEntry>,
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).
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.
32068 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)>,
32969}
33070
33171impl StyleCollector {
@@ -333,282 +73,313 @@ impl StyleCollector {
33373 StyleCollector {
33474 entries: Vec::new(),
33575 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);
34776 }
34877 }
34978
35079 /// Returns a class name for this style combination, or None if all empty.
80+ #[allow(clippy::too_many_arguments)]
35181 fn get_class(
35282 &mut self,
353− defaults: String,
354− mut rules: Vec<(Condition, String)>,
355− distinct: String,
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)>,
35693 ) -> Option<String> {
357− rules.retain(|(_, body)| !body.is_empty());
358− if defaults.is_empty() && rules.is_empty() {
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+ {
359105 return None;
360106 }
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) {
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) {
365122 for &idx in indices {
366123 let e = &self.entries[idx];
367− if e.defaults == defaults && e.rules == rules && e.distinct == distinct {
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+ {
368135 return Some(e.class_name.clone());
369136 }
370137 }
371138 }
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
375139 let idx = self.entries.len();
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());
140+ let name = short_class_name(idx);
381141 self.entries.push(StyleEntry {
382142 class_name: name.clone(),
383− style,
384− defaults,
385− rules,
386− distinct,
143+ base,
144+ pseudo,
145+ responsive,
146+ dark,
147+ print,
148+ motion_safe,
149+ motion_reduce,
150+ landscape,
151+ portrait,
152+ container,
387153 });
388− self.index.entry(style).or_default().push(idx);
154+ self.index.entry(sig).or_default().push(idx);
389155 Some(name)
390156 }
391157
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− }
399−
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(","));
423− if dev {
424− kind.push_str(&format!(" {} {{{}}}\n", selector, body));
425− } else {
426− kind.push_str(&format!("{}{{{}}}", selector, body));
158+ /// All generated rules, wrapped in `@layer htmlang`.
159+ fn to_css_formatted(&self, dev: bool) -> String {
160+ let mut css = String::new();
161+ let inner_indent = if dev { " " } else { "" };
162+ css.push_str(if dev { "@layer htmlang {\n" } else { "@layer htmlang{" });
163+
164+ // Non-responsive rules. Base and pseudo rules are merged separately by
165+ // identical body so that e.g. `.a,.b{display:flex;flex-direction:column;}`
166+ // replaces two identical rules. Pseudo variants are grouped per selector
167+ // suffix (`:hover` with `:hover`, etc.) to keep each pseudo's cascade
168+ // position independent of others.
169+ let mut base_pairs: Vec<(&str, &str)> = Vec::with_capacity(self.entries.len());
170+ for e in &self.entries {
171+ if !e.base.is_empty() {
172+ base_pairs.push((e.class_name.as_str(), e.base.as_str()));
427173 }
428174 }
175+ emit_grouped_rules(&mut css, &base_pairs, "", inner_indent, dev);
429176
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));
177+ // Collect pseudo rules grouped by selector suffix, preserving the order
178+ // in which suffixes first appear across entries.
179+ let mut pseudo_order: Vec<&str> = Vec::new();
180+ let mut pseudo_buckets: HashMap<&str, Vec<(&str, &str)>> = HashMap::new();
181+ for e in &self.entries {
182+ for (selector, body) in &e.pseudo {
183+ if body.is_empty() {
184+ continue;
185+ }
186+ let key = selector.as_str();
187+ if !pseudo_buckets.contains_key(key) {
188+ pseudo_order.push(key);
189+ }
190+ pseudo_buckets
191+ .entry(key)
192+ .or_default()
193+ .push((e.class_name.as_str(), body.as_str()));
438194 }
439195 }
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;
449− }
450− if dev {
451− css.push_str(&format!("@layer {} {{\n{}}}\n", name, rules));
452− } else {
453− css.push_str(&format!("@layer {}{{{}}}", name, rules));
196+ for selector in &pseudo_order {
197+ if let Some(pairs) = pseudo_buckets.get(selector) {
198+ emit_grouped_rules(&mut css, pairs, selector, inner_indent, dev);
454199 }
455200 }
456− css
457− }
458201
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− }
202+ // Responsive rules grouped by breakpoint
203+ for &(bp_name, bp_width) in BREAKPOINTS {
204+ let mut bp_pairs: Vec<(&str, &str)> = Vec::new();
205+ for e in &self.entries {
206+ for (bp, rule_css) in &e.responsive {
207+ if bp == bp_name && !rule_css.is_empty() {
208+ bp_pairs.push((e.class_name.as_str(), rule_css.as_str()));
538209 }
539210 }
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 { "}" });
554− }
555− } else {
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;
567211 }
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− };
212+ emit_media_block(
213+ &mut css,
214+ &format!("@media (min-width: {})", bp_width),
215+ &format!("@media(min-width:{})", bp_width),
216+ &bp_pairs,
217+ "",
218+ dev,
219+ );
220+ }
221+
222+ // Dark mode rules
223+ let dark_pairs: Vec<(&str, &str)> = self
224+ .entries
225+ .iter()
226+ .filter(|e| !e.dark.is_empty())
227+ .map(|e| (e.class_name.as_str(), e.dark.as_str()))
228+ .collect();
229+ emit_media_block(
230+ &mut css,
231+ "@media (prefers-color-scheme: dark)",
232+ "@media(prefers-color-scheme:dark)",
233+ &dark_pairs,
234+ "",
235+ dev,
236+ );
237+
238+ // Print rules
239+ let print_pairs: Vec<(&str, &str)> = self
240+ .entries
241+ .iter()
242+ .filter(|e| !e.print.is_empty())
243+ .map(|e| (e.class_name.as_str(), e.print.as_str()))
244+ .collect();
245+ emit_media_block(
246+ &mut css,
247+ "@media print",
248+ "@media print",
249+ &print_pairs,
250+ "",
251+ dev,
252+ );
253+
254+ // Motion safe rules
255+ let motion_safe_pairs: Vec<(&str, &str)> = self
256+ .entries
257+ .iter()
258+ .filter(|e| !e.motion_safe.is_empty())
259+ .map(|e| (e.class_name.as_str(), e.motion_safe.as_str()))
260+ .collect();
261+ emit_media_block(
262+ &mut css,
263+ "@media (prefers-reduced-motion: no-preference)",
264+ "@media(prefers-reduced-motion:no-preference)",
265+ &motion_safe_pairs,
266+ "",
267+ dev,
268+ );
269+
270+ // Motion reduce rules
271+ let motion_reduce_pairs: Vec<(&str, &str)> = self
272+ .entries
273+ .iter()
274+ .filter(|e| !e.motion_reduce.is_empty())
275+ .map(|e| (e.class_name.as_str(), e.motion_reduce.as_str()))
276+ .collect();
277+ emit_media_block(
278+ &mut css,
279+ "@media (prefers-reduced-motion: reduce)",
280+ "@media(prefers-reduced-motion:reduce)",
281+ &motion_reduce_pairs,
282+ "",
283+ dev,
284+ );
285+
286+ // Landscape rules
287+ let landscape_pairs: Vec<(&str, &str)> = self
288+ .entries
289+ .iter()
290+ .filter(|e| !e.landscape.is_empty())
291+ .map(|e| (e.class_name.as_str(), e.landscape.as_str()))
292+ .collect();
293+ emit_media_block(
294+ &mut css,
295+ "@media (orientation: landscape)",
296+ "@media(orientation:landscape)",
297+ &landscape_pairs,
298+ "",
299+ dev,
300+ );
301+
302+ // Portrait rules
303+ let portrait_pairs: Vec<(&str, &str)> = self
304+ .entries
305+ .iter()
306+ .filter(|e| !e.portrait.is_empty())
307+ .map(|e| (e.class_name.as_str(), e.portrait.as_str()))
308+ .collect();
309+ emit_media_block(
310+ &mut css,
311+ "@media (orientation: portrait)",
312+ "@media(orientation:portrait)",
313+ &portrait_pairs,
314+ "",
315+ dev,
316+ );
317+
318+ // Container query rules grouped by breakpoint
319+ for &(bp_name, bp_width) in BREAKPOINTS {
320+ let mut cq_pairs: Vec<(&str, &str)> = Vec::new();
321+ for e in &self.entries {
322+ for (bp, rule_css) in &e.container {
323+ if bp == bp_name && !rule_css.is_empty() {
324+ cq_pairs.push((e.class_name.as_str(), rule_css.as_str()));
325+ }
326+ }
580327 }
581− css.push_str(&inner);
328+ emit_media_block(
329+ &mut css,
330+ &format!("@container (min-width: {})", bp_width),
331+ &format!("@container(min-width:{})", bp_width),
332+ &cq_pairs,
333+ "",
334+ dev,
335+ );
582336 }
337+
338+ css.push_str(if dev { "}\n" } else { "}" });
583339 css
584340 }
585341}
586342
587−/// Emit CSS rules from `(selector, body)` pairs, merging identical bodies
343+/// Emit CSS rules from `(class_name, body)` pairs, merging identical bodies
588344/// into a single selector-list rule (e.g. `.a,.b{body}`). The first occurrence
589345/// of each distinct body determines ordering, so output stays deterministic
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) {
346+/// across runs. `selector_suffix` is appended to each class (e.g. `":hover"`,
347+/// or `""` for plain class rules). `indent` is prepended to each rule line.
348+fn emit_grouped_rules(
349+ out: &mut String,
350+ pairs: &[(&str, &str)],
351+ selector_suffix: &str,
352+ indent: &str,
353+ dev: bool,
354+) {
592355 if pairs.is_empty() {
593356 return;
594357 }
595358 // Group in first-occurrence order.
596359 let mut order: Vec<&str> = Vec::new();
597360 let mut groups: HashMap<&str, Vec<&str>> = HashMap::new();
598− for (selector, body) in pairs {
361+ for &(name, body) in pairs {
599362 if body.is_empty() {
600363 continue;
601364 }
602365 if !groups.contains_key(body) {
603366 order.push(body);
604367 }
605− groups.entry(body).or_default().push(selector);
368+ groups.entry(body).or_default().push(name);
606369 }
607370 let sp = if dev { " " } else { "" };
608371 let nl = if dev { "\n" } else { "" };
609372 for body in &order {
373+ let names = &groups[body];
610374 out.push_str(indent);
611− out.push_str(&groups[body].join(","));
375+ for (i, n) in names.iter().enumerate() {
376+ if i > 0 {
377+ out.push(',');
378+ }
379+ out.push('.');
380+ out.push_str(n);
381+ out.push_str(selector_suffix);
382+ }
612383 out.push_str(sp);
613384 out.push('{');
614385 out.push_str(body);
@@ -617,44 +388,38 @@ fn emit_grouped_rules(out: &mut String, pairs: &[(String, &str)], indent: &str,
617388 }
618389}
619390
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;
391+/// Emit an `@media` / `@container` block containing grouped class rules.
392+/// Skips the block entirely if no non-empty bodies are present.
393+fn emit_media_block(
394+ out: &mut String,
395+ header_dev: &str,
396+ header_min: &str,
397+ pairs: &[(&str, &str)],
398+ selector_suffix: &str,
399+ dev: bool,
400+) {
401+ if pairs.iter().all(|(_, body)| body.is_empty()) {
402+ return;
403+ }
404+ let mut inner = String::new();
405+ let inner_indent = if dev { " " } else { "" };
406+ emit_grouped_rules(&mut inner, pairs, selector_suffix, inner_indent, dev);
407+ if inner.is_empty() {
408+ return;
409+ }
410+ if dev {
411+ out.push_str(&format!("{} {{\n{}}}\n", header_dev, inner));
412+ } else {
413+ out.push_str(&format!("{}{{{}}}", header_min, inner));
643414 }
644415}
645416
646417struct GenContext {
647418 dev: bool,
648419 depth: usize,
420+ image_count: usize,
649421 has_interactive: 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,
422+ has_defer: bool,
658423}
659424
660425impl GenContext {
@@ -680,26 +445,23 @@ pub struct CodegenOptions {
680445 pub dev: bool,
681446 pub partial: bool,
682447 pub minify: bool,
448+ pub compat: bool,
683449}
684450
685451/// Generate HTML from a parsed document using the given options.
686452pub 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();
694453 let mut html = if opts.partial {
695− generate_partial_inner(doc, opts.dev, &mut classes)
454+ generate_partial_inner(doc, opts.dev)
696455 } else {
697− generate_full_inner(doc, opts.dev, &mut classes)
456+ generate_full_inner(doc, opts.dev)
698457 };
699458 if opts.minify {
700459 html = minify_html(&html);
701460 }
702− (html, classes)
461+ if opts.compat {
462+ html = add_vendor_prefixes(&html);
463+ }
464+ html
703465}
704466
705467pub fn generate(doc: &Document) -> String {
@@ -747,6 +509,38 @@ pub fn generate_minified(doc: &Document) -> String {
747509 )
748510}
749511
512+pub fn generate_compat(doc: &Document) -> String {
513+ generate_with(
514+ doc,
515+ &CodegenOptions {
516+ compat: true,
517+ ..Default::default()
518+ },
519+ )
520+}
521+
522+pub fn generate_dev_compat(doc: &Document) -> String {
523+ generate_with(
524+ doc,
525+ &CodegenOptions {
526+ dev: true,
527+ compat: true,
528+ ..Default::default()
529+ },
530+ )
531+}
532+
533+pub fn generate_minified_compat(doc: &Document) -> String {
534+ generate_with(
535+ doc,
536+ &CodegenOptions {
537+ minify: true,
538+ compat: true,
539+ ..Default::default()
540+ },
541+ )
542+}
543+
750544fn minify_html(html: &str) -> String {
751545 let mut result = String::with_capacity(html.len());
752546 let mut in_pre = false;
@@ -825,149 +619,578 @@ fn minify_html(html: &str) -> String {
825619 result
826620}
827621
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− };
622+/// Add vendor prefixes to CSS within <style> tags for broader browser compatibility.
623+fn add_vendor_prefixes(html: &str) -> String {
624+ // Find CSS within <style>...</style> and add vendor prefixes
625+ let mut result = String::with_capacity(html.len() + 512);
626+ let mut rest = html;
627+ while let Some(start) = rest.find("<style>") {
628+ let after_tag = start + 7;
629+ result.push_str(&rest[..after_tag]);
630+ rest = &rest[after_tag..];
631+ if let Some(end) = rest.find("</style>") {
632+ let css = &rest[..end];
633+ result.push_str(&prefix_css(css));
634+ result.push_str("</style>");
635+ rest = &rest[end + 8..];
636+ } else {
637+ break;
638+ }
639+ }
640+ result.push_str(rest);
641+ result
642+}
643+
644+fn prefix_css(css: &str) -> String {
645+ let mut out = String::with_capacity(css.len() + 256);
646+ let mut i = 0;
647+ let bytes = css.as_bytes();
648+ while i < bytes.len() {
649+ // Find property declarations
650+ if let Some(pos) = css[i..].find('{') {
651+ let brace = i + pos;
652+ out.push_str(&css[i..=brace]);
653+ i = brace + 1;
654+ // Process declarations within this block
655+ if let Some(close) = css[i..].find('}') {
656+ let block = &css[i..i + close];
657+ out.push_str(&prefix_declarations(block));
658+ out.push('}');
659+ i = i + close + 1;
660+ }
661+ } else {
662+ out.push_str(&css[i..]);
663+ break;
664+ }
665+ }
666+ out
667+}
668+
669+fn prefix_declarations(block: &str) -> String {
670+ let mut out = String::with_capacity(block.len() + 128);
671+ for decl in block.split(';') {
672+ let decl = decl.trim();
673+ if decl.is_empty() {
674+ continue;
675+ }
676+ if let Some((prop, val)) = decl.split_once(':') {
677+ let prop = prop.trim();
678+ let val = val.trim();
679+ match prop {
680+ "backdrop-filter" => {
681+ out.push_str(&format!("-webkit-backdrop-filter:{};", val));
682+ out.push_str(&format!("backdrop-filter:{};", val));
683+ }
684+ "user-select" => {
685+ out.push_str(&format!("-webkit-user-select:{};", val));
686+ out.push_str(&format!("-moz-user-select:{};", val));
687+ out.push_str(&format!("user-select:{};", val));
688+ }
689+ "appearance" => {
690+ out.push_str(&format!("-webkit-appearance:{};", val));
691+ out.push_str(&format!("-moz-appearance:{};", val));
692+ out.push_str(&format!("appearance:{};", val));
693+ }
694+ "background-clip" if val.contains("text") => {
695+ out.push_str(&format!("-webkit-background-clip:{};", val));
696+ out.push_str(&format!("background-clip:{};", val));
697+ }
698+ "hyphens" => {
699+ out.push_str(&format!("-webkit-hyphens:{};", val));
700+ out.push_str(&format!("-ms-hyphens:{};", val));
701+ out.push_str(&format!("hyphens:{};", val));
702+ }
703+ "text-size-adjust" => {
704+ out.push_str(&format!("-webkit-text-size-adjust:{};", val));
705+ out.push_str(&format!("-ms-text-size-adjust:{};", val));
706+ out.push_str(&format!("text-size-adjust:{};", val));
707+ }
708+ "mask-image" | "mask-size" | "mask-repeat" | "mask-position" => {
709+ out.push_str(&format!("-webkit-{}:{};", prop, val));
710+ out.push_str(&format!("{}:{};", prop, val));
711+ }
712+ _ => {
713+ out.push_str(decl);
714+ out.push(';');
715+ }
716+ }
717+ } else {
718+ out.push_str(decl);
719+ out.push(';');
720+ }
721+ }
722+ out
723+}
724+
725+fn generate_full_inner(doc: &Document, dev: bool) -> String {
833726 let mut styles = StyleCollector::new();
834727 let mut ctx = GenContext {
835728 dev,
836729 depth: 0,
730+ image_count: 0,
837731 has_interactive: false,
838− in_text: false,
839− flow: Flow::default(),
840− in_picture: false,
732+ has_defer: false,
841733 };
842734
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;
735+ // Check if document has @main for skip-to-content link
736+ let has_main = has_tag(&doc.nodes, "main");
866737
867738 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− );
875739
876− let element_css = build_element_css(doc, &styles, dev);
877− let nl = if dev { "\n" } else { "" };
878−
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);
740+ // Skip-to-content link for accessibility (only when @main exists)
741+ if has_main {
742+ if dev {
743+ body.push_str("<a href=\"#hl-main\" class=\"hl-skip\">Skip to content</a>\n");
744+ } else {
745+ body.push_str("<a href=\"#hl-main\" class=\"hl-skip\">Skip to content</a>");
746+ }
918747 }
919748
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);
749+ for node in &doc.nodes {
750+ generate_node(node, None, &mut body, &mut styles, &mut ctx);
924751 }
925− let mut body_attrs = String::new();
926− emit_class_attr(&mut body_attrs, body_class.as_deref(), None);
927752
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− )
941− }
942− } else {
753+ // Collect external domains for DNS prefetch
754+ let dns_prefetch_html = collect_dns_prefetch(&body, dev);
755+
756+ let element_css = build_element_css(doc, &styles, dev);
757+
758+ // Build meta tags string
759+ let meta_html = if doc.meta_tags.is_empty() {
943760 String::new()
761+ } else {
762+ let mut m = String::new();
763+ for (name, content) in &doc.meta_tags {
764+ if dev {
765+ m.push_str(&format!(
766+ "<meta name=\"{}\" content=\"{}\">\n",
767+ html_escape(name),
768+ html_escape(content)
769+ ));
770+ } else {
771+ m.push_str(&format!(
772+ "<meta name=\"{}\" content=\"{}\">",
773+ html_escape(name),
774+ html_escape(content)
775+ ));
776+ }
777+ }
778+ m
944779 };
945− let reset_css = reset_css(dev, true, &focus_visible_css);
946− classes.extend(styles.classes());
947−
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−}
954780
955−/// Assemble every CSS block the document needs (font faces, custom
956−/// properties, generated class rules, keyframes, and user CSS). Shared by
957−/// full-page and partial output so both emit the same styles.
958−fn build_element_css(doc: &Document, styles: &StyleCollector, dev: bool) -> String {
959− let mut element_css = String::new();
781+ // Build OG meta tags
782+ let og_html = if doc.og_tags.is_empty() {
783+ String::new()
784+ } else {
785+ let mut o = String::new();
786+ for (property, content) in &doc.og_tags {
787+ if dev {
788+ o.push_str(&format!(
789+ "<meta property=\"og:{}\" content=\"{}\">\n",
790+ html_escape(property),
791+ html_escape(content)
792+ ));
793+ } else {
794+ o.push_str(&format!(
795+ "<meta property=\"og:{}\" content=\"{}\">",
796+ html_escape(property),
797+ html_escape(content)
798+ ));
799+ }
800+ }
801+ o
802+ };
960803
961− // Collect the CSS custom properties declared with `@let --name` so they
962− // can be emitted in a single `:root` block below.
963− let mut root_vars: Vec<(String, String)> = Vec::new();
964− for (name, value) in &doc.css_vars {
965− root_vars.push((name.clone(), value.clone()));
966− }
804+ // Build head blocks string
805+ let head_html = if doc.head_blocks.is_empty() {
806+ String::new()
807+ } else {
808+ let mut h = String::new();
809+ for block in &doc.head_blocks {
810+ h.push_str(block);
811+ if dev {
812+ h.push('\n');
813+ }
814+ }
815+ h
816+ };
967817
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);
818+ let lang_attr = match &doc.lang {
819+ Some(lang) => format!(" lang=\"{}\"", html_escape(lang)),
820+ None => String::new(),
821+ };
822+
823+ let favicon_html = match &doc.favicon {
824+ Some(path) => {
825+ // Try to read and inline the favicon
826+ if let Ok(data) = std::fs::read(path) {
827+ let mime = if path.ends_with(".ico") {
828+ "image/x-icon"
829+ } else if path.ends_with(".png") {
830+ "image/png"
831+ } else if path.ends_with(".svg") {
832+ "image/svg+xml"
833+ } else {
834+ "image/x-icon"
835+ };
836+ let b64 = base64_encode(&data);
837+ if dev {
838+ format!(
839+ "<link rel=\"icon\" href=\"data:{};base64,{}\">\n",
840+ mime, b64
841+ )
842+ } else {
843+ format!("<link rel=\"icon\" href=\"data:{};base64,{}\">", mime, b64)
844+ }
845+ } else {
846+ // Fall back to href
847+ if dev {
848+ format!("<link rel=\"icon\" href=\"{}\">\n", html_escape(path))
849+ } else {
850+ format!("<link rel=\"icon\" href=\"{}\">", html_escape(path))
851+ }
852+ }
853+ }
854+ None => String::new(),
855+ };
856+
857+ // Canonical URL
858+ let canonical_html = match &doc.canonical {
859+ Some(url) => {
860+ if dev {
861+ format!("<link rel=\"canonical\" href=\"{}\">\n", html_escape(url))
862+ } else {
863+ format!("<link rel=\"canonical\" href=\"{}\">", html_escape(url))
864+ }
865+ }
866+ None => String::new(),
867+ };
868+
869+ // Base URL
870+ let base_html = match &doc.base_url {
871+ Some(url) => {
872+ if dev {
873+ format!("<base href=\"{}\">\n", html_escape(url))
874+ } else {
875+ format!("<base href=\"{}\">", html_escape(url))
876+ }
877+ }
878+ None => String::new(),
879+ };
880+
881+ // JSON-LD blocks
882+ let json_ld_html: String = doc
883+ .json_ld_blocks
884+ .iter()
885+ .map(|block| {
886+ if dev {
887+ format!(
888+ "<script type=\"application/ld+json\">\n{}\n</script>\n",
889+ block
890+ )
891+ } else {
892+ format!("<script type=\"application/ld+json\">{}</script>", block)
893+ }
894+ })
895+ .collect();
896+
897+ // Manifest link
898+ let manifest_html = if let Some(ref manifest) = doc.manifest {
899+ let mut json = String::from("{");
900+ json.push_str(&format!("\"name\":{},", json_str(&manifest.name)));
901+ if let Some(ref short) = manifest.short_name {
902+ json.push_str(&format!("\"short_name\":{},", json_str(short)));
903+ }
904+ json.push_str(&format!("\"start_url\":{},", json_str(&manifest.start_url)));
905+ json.push_str(&format!("\"display\":{}", json_str(&manifest.display)));
906+ if let Some(ref bg) = manifest.background_color {
907+ json.push_str(&format!(",\"background_color\":{}", json_str(bg)));
908+ }
909+ if let Some(ref tc) = manifest.theme_color {
910+ json.push_str(&format!(",\"theme_color\":{}", json_str(tc)));
911+ }
912+ if let Some(ref desc) = manifest.description {
913+ json.push_str(&format!(",\"description\":{}", json_str(desc)));
914+ }
915+ if !manifest.icons.is_empty() {
916+ json.push_str(",\"icons\":[");
917+ for (i, (src, sizes)) in manifest.icons.iter().enumerate() {
918+ if i > 0 {
919+ json.push(',');
920+ }
921+ json.push_str(&format!(
922+ "{{\"src\":{},\"sizes\":{},\"type\":\"image/png\"}}",
923+ json_str(src),
924+ json_str(sizes)
925+ ));
926+ }
927+ json.push(']');
928+ }
929+ json.push('}');
930+
931+ // Inline the manifest as a data URI
932+ let encoded = base64_encode(json.as_bytes());
933+ if dev {
934+ format!(
935+ "<link rel=\"manifest\" href=\"data:application/manifest+json;base64,{}\">\n",
936+ encoded
937+ )
938+ } else {
939+ format!(
940+ "<link rel=\"manifest\" href=\"data:application/manifest+json;base64,{}\">",
941+ encoded
942+ )
943+ }
944+ } else {
945+ String::new()
946+ };
947+
948+ // Preload hints (auto-detect fonts from @font-face)
949+ let mut preload_html = String::new();
950+ for (_, url) in &doc.font_faces {
951+ if dev {
952+ preload_html.push_str(&format!(
953+ "<link rel=\"preload\" href=\"{}\" as=\"font\" type=\"font/woff2\" crossorigin>\n",
954+ url
955+ ));
956+ } else {
957+ preload_html.push_str(&format!(
958+ "<link rel=\"preload\" href=\"{}\" as=\"font\" type=\"font/woff2\" crossorigin>",
959+ url
960+ ));
961+ }
962+ }
963+ // Explicit preload hints from the document
964+ for hint in &doc.preload_hints {
965+ if dev {
966+ preload_html.push_str(&format!(
967+ "<link rel=\"preload\" href=\"{}\" as=\"{}\"{}>\n",
968+ html_escape(&hint.href),
969+ hint.as_type,
970+ if hint.crossorigin { " crossorigin" } else { "" }
971+ ));
972+ } else {
973+ preload_html.push_str(&format!(
974+ "<link rel=\"preload\" href=\"{}\" as=\"{}\"{}>",
975+ html_escape(&hint.href),
976+ hint.as_type,
977+ if hint.crossorigin { " crossorigin" } else { "" }
978+ ));
979+ }
980+ }
981+
982+ // Auto theme-color meta from @theme primary token
983+ let theme_color_html = doc
984+ .theme_tokens
985+ .iter()
986+ .find(|(name, _)| name == "primary" || name == "theme-color")
987+ .map(|(_, value)| {
988+ if dev {
989+ format!(
990+ "<meta name=\"theme-color\" content=\"{}\">\n",
991+ html_escape(value)
992+ )
993+ } else {
994+ format!(
995+ "<meta name=\"theme-color\" content=\"{}\">",
996+ html_escape(value)
997+ )
998+ }
999+ })
1000+ .unwrap_or_default();
1001+
1002+ // Focus-visible CSS for interactive elements (accessibility)
1003+ let focus_visible_css = if ctx.has_interactive {
1004+ if dev {
1005+ "a:focus-visible, button:focus-visible, input:focus-visible, select:focus-visible, textarea:focus-visible { outline: 2px solid currentColor; outline-offset: 2px; }\n"
1006+ } else {
1007+ "a:focus-visible,button:focus-visible,input:focus-visible,select:focus-visible,textarea:focus-visible{outline:2px solid currentColor;outline-offset:2px}"
1008+ }
1009+ } else {
1010+ ""
1011+ };
1012+
1013+ // Skip-to-content CSS (visually hidden but accessible)
1014+ let skip_link_css = if has_main {
1015+ if dev {
1016+ ".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"
1017+ } else {
1018+ ".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}"
1019+ }
1020+ } else {
1021+ ""
1022+ };
1023+
1024+ // Noscript fallback: show deferred content if JS is disabled
1025+ let noscript_html = if ctx.has_defer {
1026+ if dev {
1027+ "<noscript><style>.hl-defer-placeholder { display: none; }</style></noscript>\n"
1028+ } else {
1029+ "<noscript><style>.hl-defer-placeholder{display:none}</style></noscript>"
1030+ }
1031+ } else {
1032+ ""
1033+ };
1034+
1035+ let reset_css = reset_css(dev, focus_visible_css, skip_link_css);
1036+
1037+ match &doc.page_title {
1038+ Some(title) => {
1039+ if dev {
1040+ format!(
1041+ "\
1042+<!DOCTYPE html>
1043+<html{lang_attr}>
1044+<head>
1045+<meta charset=\"utf-8\">
1046+<meta name=\"viewport\" content=\"width=device-width, initial-scale=1\">
1047+<title>{title}</title>
1048+{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}\
1049+<style>
1050+{reset_css}{element_css}\
1051+</style>
1052+{noscript_html}\
1053+</head>
1054+<body>
1055+{body}\
1056+</body>
1057+</html>
1058+",
1059+ title = html_escape(title),
1060+ lang_attr = lang_attr,
1061+ theme_color_html = theme_color_html,
1062+ base_html = base_html,
1063+ canonical_html = canonical_html,
1064+ manifest_html = manifest_html,
1065+ preload_html = preload_html,
1066+ dns_prefetch_html = dns_prefetch_html,
1067+ meta_html = meta_html,
1068+ favicon_html = favicon_html,
1069+ json_ld_html = json_ld_html,
1070+ head_html = head_html,
1071+ og_html = og_html,
1072+ reset_css = reset_css,
1073+ noscript_html = noscript_html,
1074+ element_css = element_css,
1075+ body = body,
1076+ )
1077+ } else {
1078+ format!(
1079+ "<!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>",
1080+ title = html_escape(title),
1081+ lang_attr = lang_attr,
1082+ theme_color_html = theme_color_html,
1083+ base_html = base_html,
1084+ canonical_html = canonical_html,
1085+ manifest_html = manifest_html,
1086+ preload_html = preload_html,
1087+ dns_prefetch_html = dns_prefetch_html,
1088+ meta_html = meta_html,
1089+ og_html = og_html,
1090+ favicon_html = favicon_html,
1091+ json_ld_html = json_ld_html,
1092+ head_html = head_html,
1093+ reset_css = reset_css,
1094+ noscript_html = noscript_html,
1095+ element_css = element_css,
1096+ body = body,
1097+ )
1098+ }
1099+ }
1100+ None => {
1101+ if element_css.is_empty() {
1102+ body
1103+ } else if dev {
1104+ format!("<style>\n{}</style>\n{}", element_css, body)
1105+ } else {
1106+ format!("<style>{}</style>{}", element_css, body)
1107+ }
1108+ }
1109+ }
1110+}
1111+
1112+/// Encode `s` as a JSON string literal (with surrounding quotes).
1113+pub(crate) fn json_str(s: &str) -> String {
1114+ let mut out = String::with_capacity(s.len() + 2);
1115+ out.push('"');
1116+ for c in s.chars() {
1117+ match c {
1118+ '"' => out.push_str("\\\""),
1119+ '\\' => out.push_str("\\\\"),
1120+ '\n' => out.push_str("\\n"),
1121+ '\r' => out.push_str("\\r"),
1122+ '\t' => out.push_str("\\t"),
1123+ c if (c as u32) < 0x20 => out.push_str(&format!("\\u{:04x}", c as u32)),
1124+ c => out.push(c),
1125+ }
1126+ }
1127+ out.push('"');
1128+ out
1129+}
1130+
1131+/// Assemble every CSS block the document needs (font faces, custom
1132+/// properties, generated class rules, keyframes, and user CSS). Shared by
1133+/// full-page and partial output so both emit the same styles.
1134+fn build_element_css(doc: &Document, styles: &StyleCollector, dev: bool) -> String {
1135+ let mut element_css = String::new();
1136+
1137+ // @font-face rules, in declaration order
1138+ for (name, url) in &doc.font_faces {
1139+ let format_hint = if url.ends_with(".woff2") {
1140+ " format('woff2')"
1141+ } else if url.ends_with(".woff") {
1142+ " format('woff')"
1143+ } else if url.ends_with(".ttf") {
1144+ " format('truetype')"
1145+ } else if url.ends_with(".otf") {
1146+ " format('opentype')"
1147+ } else {
1148+ ""
1149+ };
1150+ if dev {
1151+ element_css.push_str(&format!(
1152+ "@font-face {{\n font-family: '{}';\n src: url('{}'){};\n font-display: swap;\n}}\n",
1153+ name, url, format_hint
1154+ ));
1155+ } else {
1156+ element_css.push_str(&format!(
1157+ "@font-face{{font-family:'{}';src:url('{}'){};font-display:swap}}",
1158+ name, url, format_hint
1159+ ));
1160+ }
1161+ }
1162+
1163+ // Collect all CSS custom properties (explicit `@let --name` / `@theme`
1164+ // tokens, plus any auto-extracted repeats) so they can be emitted in a
1165+ // single `:root` block below.
1166+ let mut root_vars: Vec<(String, String)> = Vec::new();
1167+ for (name, value) in &doc.css_vars {
1168+ root_vars.push((name.clone(), value.clone()));
1169+ }
1170+ for (name, value) in &doc.theme_tokens {
1171+ let css_name = format!("--{}", name);
1172+ if !root_vars.iter().any(|(n, _)| *n == css_name) {
1173+ root_vars.push((css_name, value.clone()));
1174+ }
1175+ }
1176+
1177+ // Generated rules always go in `@layer htmlang`, so unlayered user CSS
1178+ // (`@style`, `@raw`) overrides them regardless of specificity.
1179+ let styles_css = styles.to_css_formatted(dev);
1180+ // Fold literal values declared via `@theme` / `@let --name` back into
1181+ // `var(--name)` references so the generated CSS actually uses the
1182+ // custom properties emitted in `:root`.
1183+ let styles_css = substitute_css_vars(&styles_css, &root_vars);
1184+ // Further compress the CSS by auto-extracting any remaining literal
1185+ // values that appear often enough for `var(--hN)` references to come out
1186+ // shorter overall. Disabled in dev mode to keep the CSS readable.
1187+ let styles_css = if dev {
1188+ styles_css
1189+ } else {
1190+ let (new_css, auto_vars) = auto_extract_repeats(&styles_css, &root_vars);
1191+ root_vars.extend(auto_vars);
1192+ new_css
1193+ };
9711194
9721195 // Emit the :root block first so the cascade picks up the custom
9731196 // properties before the class rules consume them.
@@ -992,121 +1215,72 @@ fn build_element_css(doc: &Document, styles: &StyleCollector, dev: bool) -> Stri
9921215
9931216 element_css.push_str(&styles_css);
9941217
1218+ // @keyframes
1219+ for (name, kf_body) in &doc.keyframes {
1220+ if dev {
1221+ element_css.push_str(&format!("@keyframes {} {{\n{}\n}}\n", name, kf_body));
1222+ } else {
1223+ element_css.push_str(&format!("@keyframes {}{{{}}}", name, kf_body));
1224+ }
1225+ }
1226+
1227+ // Auto-inject skeleton keyframe if skeleton attribute is used
1228+ if element_css.contains("hl-skeleton") {
1229+ if dev {
1230+ element_css.push_str("@keyframes hl-skeleton {\n 0% { background-position: 200% 0; }\n 100% { background-position: -200% 0; }\n}\n");
1231+ } else {
1232+ element_css.push_str("@keyframes hl-skeleton{0%{background-position:200% 0}100%{background-position:-200% 0}}");
1233+ }
1234+ }
1235+
9951236 // @style blocks (custom CSS)
9961237 for block in &doc.custom_css {
9971238 if dev {
9981239 element_css.push_str(block);
9991240 element_css.push('\n');
10001241 } else {
1001− element_css.push_str(&compact_css(block));
1242+ let minified: String = block.lines().map(|l| l.trim()).collect::<Vec<_>>().join("");
1243+ element_css.push_str(&minified);
10021244 }
10031245 }
10041246
10051247 element_css
10061248}
10071249
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(" ")
1018−}
1019−
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−
10361250/// 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− });
1058− } else {
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; }}")
1251+/// every layer, so an unlayered `a{color:inherit}` would override
1252+/// `@link [color red]`.
1253+fn reset_css(dev: bool, focus_visible_css: &str, skip_link_css: &str) -> String {
1254+ let base = if dev {
1255+ "*, *::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"
10691256 } 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);
1257+ "*,*::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}"
1258+ };
1259+ let rules = format!("{}{}{}", base, focus_visible_css, skip_link_css);
10771260 if dev {
1078− format!(
1079− "@layer {};\n@layer hl-reset {{\n{}}}\n",
1080− LAYERS.join(", "),
1081− rules
1082− )
1261+ format!("@layer hl-reset, htmlang;\n@layer hl-reset {{\n{}}}\n", rules)
10831262 } else {
1084− format!("@layer {};@layer hl-reset{{{}}}", LAYERS.join(","), rules)
1263+ format!("@layer hl-reset,htmlang;@layer hl-reset{{{}}}", rules)
10851264 }
10861265}
10871266
10881267/// Generate an HTML fragment: body + optional <style>, no <html>/<head>/<body> wrapper.
1089−fn generate_partial_inner(doc: &Document, dev: bool, classes: &mut Vec<Class>) -> String {
1268+fn generate_partial_inner(doc: &Document, dev: bool) -> String {
10901269 let mut styles = StyleCollector::new();
10911270 let mut ctx = GenContext {
10921271 dev,
10931272 depth: 0,
1273+ image_count: 0,
10941274 has_interactive: false,
1095− in_text: false,
1096− flow: Flow::default(),
1097− in_picture: false,
1275+ has_defer: false,
10981276 };
10991277 let mut body = String::new();
11001278
1101− generate_children(&doc.nodes, None, &mut body, &mut styles, &mut ctx);
1102−
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, ""));
1279+ for node in &doc.nodes {
1280+ generate_node(node, None, &mut body, &mut styles, &mut ctx);
11081281 }
1109− classes.extend(styles.classes());
1282+
1283+ let element_css = build_element_css(doc, &styles, dev);
11101284
11111285 if element_css.is_empty() {
11121286 body
@@ -1121,20 +1295,22 @@ fn generate_partial_inner(doc: &Document, dev: bool, classes: &mut Vec<Class>) -
11211295// Node generation
11221296// ---------------------------------------------------------------------------
11231297
1124−/// Write `node`, which is inside an element with the layout `parent`
1125−/// (`None` at the top of the page).
11261298fn generate_node(
11271299 node: &Node,
1128− parent: Option<Layout>,
1300+ parent_kind: Option<&ElementKind>,
11291301 out: &mut String,
11301302 styles: &mut StyleCollector,
11311303 ctx: &mut GenContext,
11321304) {
11331305 match node {
1134− Node::Element(elem) => generate_element(elem, parent, out, styles, ctx),
1306+ Node::Element(elem) => generate_element(elem, parent_kind, out, styles, ctx),
11351307 Node::Text(segments) => {
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);
1308+ let needs_wrap = matches!(
1309+ parent_kind,
1310+ Some(ElementKind::Row | ElementKind::Column | ElementKind::El)
1311+ ) || parent_kind
1312+ .and_then(ElementKind::spec)
1313+ .is_some_and(|spec| spec.wraps_text);
11381314 if needs_wrap {
11391315 out.push_str(&ctx.indent());
11401316 out.push_str("<span>");
@@ -1153,156 +1329,69 @@ fn generate_node(
11531329 }
11541330}
11551331
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−}
11701332
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);
1333+/// Emit the argument of an element whose argument is an HTML attribute
1334+/// (`@iframe URL` → `src="URL"`, `@form /submit` → `action="/submit"`).
1335+fn emit_argument_attr(out: &mut String, elem: &Element) {
1336+ if let Some(TagSpec {
1337+ arg: TagArg::Attr(attr),
1338+ ..
1339+ }) = elem.kind.spec()
1340+ && let Some(value) = &elem.argument
1341+ {
1342+ out.push(' ');
1343+ out.push_str(attr);
1344+ out.push_str("=\"");
1345+ out.push_str(&html_escape(value));
1346+ out.push('"');
1347+ }
11821348}
11831349
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);
1350+fn emit_html_passthrough_attrs(out: &mut String, attrs: &[Attribute]) {
1351+ for attr in attrs {
1352+ let key = attr.key.as_str();
1353+ if !crate::vocab::is_html_passthrough(key) {
12011354 continue;
12021355 }
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;
1356+ if crate::vocab::BOOLEAN_HTML_ATTRS.contains(&key) && attr.value.is_none() {
1357+ out.push(' ');
1358+ out.push_str(key);
1359+ } else if let Some(val) = &attr.value {
1360+ out.push(' ');
1361+ out.push_str(key);
1362+ out.push_str("=\"");
1363+ out.push_str(&html_escape(strip_string_quotes(val)));
1364+ out.push('"');
12161365 }
1217− *previous = Some(matches!(child, Node::Text(_)));
12181366 }
12191367}
12201368
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);
1266− }
1369+/// If the value is wrapped in a single pair of matching quotes (e.g.
1370+/// `"Avatar"`), return the inner content. Quotes act as source-level
1371+/// delimiters in the `.hl` syntax and shouldn't leak into HTML attribute
1372+/// values. Multi-quoted values like `"h h" "s m"` are left unchanged —
1373+/// those are real string tokens (used e.g. by CSS `grid-template-areas`).
1374+fn strip_string_quotes(val: &str) -> &str {
1375+ let bytes = val.as_bytes();
1376+ if bytes.len() < 2 {
1377+ return val;
12671378 }
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('"');
1379+ let first = bytes[0];
1380+ let last = bytes[bytes.len() - 1];
1381+ if (first == b'"' && last == b'"') || (first == b'\'' && last == b'\'') {
1382+ let inner = &val[1..val.len() - 1];
1383+ if !inner.as_bytes().contains(&first) {
1384+ return inner;
1385+ }
12941386 }
1387+ val
12951388}
12961389
12971390// True if any direct child is `@in-front` or `@behind`. Such children render
12981391// as absolutely positioned overlays, so the parent automatically becomes a
12991392// positioning context (position:relative + isolation:isolate).
13001393fn has_overlay_children(elem: &Element) -> bool {
1301− holds_overlays(&elem.children)
1302−}
1303−
1304−fn holds_overlays(children: &[Node]) -> bool {
1305− children.iter().any(|child| {
1394+ elem.children.iter().any(|child| {
13061395 matches!(
13071396 child,
13081397 Node::Element(e) if e.kind.is_tag("in-front") || e.kind.is_tag("behind")
@@ -1312,32 +1401,48 @@ fn holds_overlays(children: &[Node]) -> bool {
13121401
13131402fn generate_element(
13141403 elem: &Element,
1315− parent: Option<Layout>,
1404+ parent_kind: Option<&ElementKind>,
13161405 out: &mut String,
13171406 styles: &mut StyleCollector,
13181407 ctx: &mut GenContext,
13191408) {
13201409 // Self-closing elements
1321− if elem.kind.layout() == Layout::Void {
1322− generate_self_closing(elem, parent, out, styles, ctx);
1410+ if elem.kind == ElementKind::Image || elem.kind.spec().is_some_and(|spec| spec.void) {
1411+ generate_self_closing(elem, parent_kind, out, styles, ctx);
13231412 return;
13241413 }
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);
1414+ // @script renders as <script> with raw body content (no HTML escaping)
1415+ if elem.kind == ElementKind::Script {
13291416 out.push_str(&ctx.indent());
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)));
1417+ out.push_str("<script");
1418+ // Pass through src, type, defer, async, etc.
1419+ for attr in &elem.attrs {
1420+ let key = attr.key.as_str();
1421+ if matches!(
1422+ key,
1423+ "src"
1424+ | "type"
1425+ | "defer"
1426+ | "async"
1427+ | "crossorigin"
1428+ | "integrity"
1429+ | "nomodule"
1430+ | "id"
1431+ ) {
1432+ if let Some(val) = &attr.value {
1433+ out.push(' ');
1434+ out.push_str(key);
1435+ out.push_str("=\"");
1436+ out.push_str(&html_escape(val));
1437+ out.push('"');
1438+ } else {
1439+ out.push(' ');
1440+ out.push_str(key);
1441+ }
13371442 }
13381443 }
1339− emit_html_attrs(out, &elem.attrs);
13401444 out.push('>');
1445+ // Children are raw JS code, not HTML
13411446 for child in &elem.children {
13421447 match child {
13431448 Node::Text(segments) => {
@@ -1351,10 +1456,46 @@ fn generate_element(
13511456 _ => {}
13521457 }
13531458 }
1354− out.push_str("</");
1355− out.push_str(tag);
1459+ out.push_str("</script>");
1460+ out.push_str(ctx.nl());
1461+ return;
1462+ }
1463+ // @breadcrumb generates semantic <nav aria-label="breadcrumb"><ol>...</ol></nav>
1464+ if elem.kind == ElementKind::Breadcrumb {
1465+ let gen_class = compute_class(&elem.attrs, &elem.kind, parent_kind, styles, false);
1466+ let (id, user_class) = extract_id_class(&elem.attrs);
1467+ out.push_str(&ctx.indent());
1468+ out.push_str("<nav aria-label=\"breadcrumb\"");
1469+ emit_class_attr(out, gen_class.as_deref(), user_class.as_deref());
1470+ if let Some(id) = id {
1471+ out.push_str(" id=\"");
1472+ out.push_str(&html_escape(&id));
1473+ out.push('"');
1474+ }
13561475 out.push('>');
13571476 out.push_str(ctx.nl());
1477+ ctx.depth += 1;
1478+ out.push_str(&ctx.indent());
1479+ out.push_str("<ol>");
1480+ out.push_str(ctx.nl());
1481+ ctx.depth += 1;
1482+ for child in &elem.children {
1483+ out.push_str(&ctx.indent());
1484+ out.push_str("<li>");
1485+ let mut buf = String::new();
1486+ generate_node(child, Some(&elem.kind), &mut buf, styles, ctx);
1487+ out.push_str(buf.trim());
1488+ out.push_str("</li>");
1489+ out.push_str(ctx.nl());
1490+ }
1491+ ctx.depth -= 1;
1492+ out.push_str(&ctx.indent());
1493+ out.push_str("</ol>");
1494+ out.push_str(ctx.nl());
1495+ ctx.depth -= 1;
1496+ out.push_str(&ctx.indent());
1497+ out.push_str("</nav>");
1498+ out.push_str(ctx.nl());
13581499 return;
13591500 }
13601501 if elem.kind == ElementKind::Children {
@@ -1364,26 +1505,26 @@ fn generate_element(
13641505 return;
13651506 }
13661507 if elem.kind == ElementKind::Fragment {
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);
1508+ // Render children without a wrapper element
1509+ for child in &elem.children {
1510+ generate_node(child, parent_kind, out, styles, ctx);
1511+ }
13701512 return;
13711513 }
13721514
1373− let mut own = Flow::of(elem);
13741515 let tag = match &elem.kind {
1375− ElementKind::Row | ElementKind::El => "div",
1516+ ElementKind::Row | ElementKind::Column | ElementKind::El => "div",
13761517 ElementKind::Text => "span",
13771518 ElementKind::Paragraph => "p",
13781519 ElementKind::Link => "a",
1520+ ElementKind::Tag(spec)
1521+ if spec.name == "list" && elem.attrs.iter().any(|a| a.key == "ordered") =>
1522+ {
1523+ "ol"
1524+ }
13791525 ElementKind::Tag(spec) => spec.html,
13801526 _ => "",
13811527 };
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 };
13871528 let kind_label = elem.kind.name();
13881529
13891530 // Track interactive elements for focus-visible CSS
@@ -1394,8 +1535,14 @@ fn generate_element(
13941535 }
13951536
13961537 // Compute CSS for each state and get a class name
1397− let gen_class = element_class(elem, &Site::new(elem, parent, &ctx.flow), styles);
1398− own.class = gen_class.clone();
1538+ let overlay_children = has_overlay_children(elem);
1539+ let gen_class = compute_class(
1540+ &elem.attrs,
1541+ &elem.kind,
1542+ parent_kind,
1543+ styles,
1544+ overlay_children,
1545+ );
13991546 let (id, user_class) = extract_id_class(&elem.attrs);
14001547
14011548 if ctx.dev && elem.line_num > 0 {
@@ -1409,9 +1556,60 @@ fn generate_element(
14091556 out.push('<');
14101557 out.push_str(tag);
14111558
1412− emit_argument_attr(out, elem, ctx.in_picture);
1559+ // @main gets id="hl-main" for skip-to-content link (unless user set an id)
1560+ if elem.kind.is_tag("main") && id.is_none() {
1561+ out.push_str(" id=\"hl-main\"");
1562+ }
14131563
1414− emit_class_attr(out, gen_class.as_deref(), user_class.as_deref());
1564+ if elem.kind == ElementKind::Link
1565+ && let Some(url) = &elem.argument
1566+ {
1567+ out.push_str(" href=\"");
1568+ out.push_str(&html_escape(url));
1569+ out.push('"');
1570+ // Auto rel="noopener noreferrer" and target="_blank" for external links
1571+ let is_external = url.starts_with("http://") || url.starts_with("https://");
1572+ if is_external {
1573+ let has_rel = elem.attrs.iter().any(|a| a.key == "rel");
1574+ let has_target = elem.attrs.iter().any(|a| a.key == "target");
1575+ if !has_rel {
1576+ out.push_str(" rel=\"noopener noreferrer\"");
1577+ }
1578+ if !has_target {
1579+ out.push_str(" target=\"_blank\"");
1580+ }
1581+ }
1582+ }
1583+
1584+ emit_argument_attr(out, elem);
1585+
1586+ // Tooltip title
1587+ if elem.kind.is_tag("tooltip")
1588+ && let Some(text) = &elem.argument
1589+ {
1590+ out.push_str(" title=\"");
1591+ out.push_str(&html_escape(text));
1592+ out.push('"');
1593+ }
1594+
1595+ // Critical CSS: inline styles directly instead of using a class
1596+ let is_critical = elem.attrs.iter().any(|a| a.key == "critical");
1597+ if is_critical {
1598+ let inline_css = attrs_to_css(&elem.attrs, "", &elem.kind, parent_kind, overlay_children);
1599+ if !inline_css.is_empty() {
1600+ out.push_str(" style=\"");
1601+ out.push_str(&html_escape(&inline_css));
1602+ out.push('"');
1603+ }
1604+ // Still use class for non-base styles (pseudo, responsive, etc.)
1605+ if gen_class.as_deref().is_some_and(|c| !c.is_empty()) {
1606+ emit_class_attr(out, gen_class.as_deref(), user_class.as_deref());
1607+ } else if let Some(ref uc) = user_class {
1608+ emit_class_attr(out, None, Some(uc));
1609+ }
1610+ } else {
1611+ emit_class_attr(out, gen_class.as_deref(), user_class.as_deref());
1612+ }
14151613
14161614 if let Some(id) = id {
14171615 out.push_str(" id=\"");
@@ -1419,7 +1617,7 @@ fn generate_element(
14191617 out.push('"');
14201618 }
14211619
1422− emit_html_attrs(out, &elem.attrs);
1620+ emit_html_passthrough_attrs(out, &elem.attrs);
14231621
14241622 // Source map attributes in dev mode
14251623 if ctx.dev && elem.line_num > 0 {
@@ -1430,27 +1628,28 @@ fn generate_element(
14301628 }
14311629
14321630 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");
14381631 out.push_str(ctx.nl());
14391632
1440− let layout = elem.kind.layout();
1633+ // Inline text argument
1634+ if renders_argument_as_text(&elem.kind)
1635+ && let Some(text) = &elem.argument
1636+ {
1637+ out.push_str(&html_escape(text));
1638+ }
1639+
1640+ // Children
14411641 ctx.depth += 1;
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;
1642+ let is_paragraph = elem.kind == ElementKind::Paragraph
1643+ || elem.kind.spec().is_some_and(|spec| spec.inline);
1644+ for (i, child) in elem.children.iter().enumerate() {
1645+ generate_node(child, Some(&elem.kind), out, styles, ctx);
1646+ if is_paragraph && i < elem.children.len() - 1 {
1647+ out.push(' ');
1648+ }
1649+ }
14501650 ctx.depth -= 1;
14511651
14521652 out.push_str(&ctx.indent());
1453− ctx.dev = outer_dev;
14541653 out.push_str("</");
14551654 out.push_str(tag);
14561655 out.push('>');
@@ -1459,12 +1658,12 @@ fn generate_element(
14591658
14601659fn generate_self_closing(
14611660 elem: &Element,
1462− parent: Option<Layout>,
1661+ parent_kind: Option<&ElementKind>,
14631662 out: &mut String,
14641663 styles: &mut StyleCollector,
14651664 ctx: &mut GenContext,
14661665) {
1467− let gen_class = element_class(elem, &Site::new(elem, parent, &ctx.flow), styles);
1666+ let gen_class = compute_class(&elem.attrs, &elem.kind, parent_kind, styles, false);
14681667 let (id, user_class) = extract_id_class(&elem.attrs);
14691668
14701669 let (tag, kind_label) = match &elem.kind {
@@ -1483,7 +1682,44 @@ fn generate_self_closing(
14831682 out.push_str(&ctx.indent());
14841683 out.push('<');
14851684 out.push_str(tag);
1486− emit_argument_attr(out, elem, ctx.in_picture);
1685+ emit_argument_attr(out, elem);
1686+
1687+ // Image src (with optional non-SVG base64 inlining)
1688+ if elem.kind == ElementKind::Image {
1689+ let src = elem.argument.as_deref().unwrap_or("");
1690+ let is_inline = elem.attrs.iter().any(|a| a.key == "inline");
1691+ if is_inline && !src.is_empty() && !src.ends_with(".svg") {
1692+ let mime = if src.ends_with(".png") {
1693+ "image/png"
1694+ } else if src.ends_with(".jpg") || src.ends_with(".jpeg") {
1695+ "image/jpeg"
1696+ } else if src.ends_with(".gif") {
1697+ "image/gif"
1698+ } else if src.ends_with(".webp") {
1699+ "image/webp"
1700+ } else if src.ends_with(".avif") {
1701+ "image/avif"
1702+ } else {
1703+ "application/octet-stream"
1704+ };
1705+ if let Ok(data) = std::fs::read(src) {
1706+ let b64 = base64_encode(&data);
1707+ out.push_str(" src=\"data:");
1708+ out.push_str(mime);
1709+ out.push_str(";base64,");
1710+ out.push_str(&b64);
1711+ out.push('"');
1712+ } else {
1713+ out.push_str(" src=\"");
1714+ out.push_str(&html_escape(src));
1715+ out.push('"');
1716+ }
1717+ } else {
1718+ out.push_str(" src=\"");
1719+ out.push_str(&html_escape(src));
1720+ out.push('"');
1721+ }
1722+ }
14871723
14881724 emit_class_attr(out, gen_class.as_deref(), user_class.as_deref());
14891725
@@ -1493,7 +1729,7 @@ fn generate_self_closing(
14931729 out.push('"');
14941730 }
14951731
1496− emit_html_attrs(out, &elem.attrs);
1732+ emit_html_passthrough_attrs(out, &elem.attrs);
14971733
14981734 // Source map attributes in dev mode (self-closing)
14991735 if ctx.dev && elem.line_num > 0 {
@@ -1503,8 +1739,95 @@ fn generate_self_closing(
15031739 ));
15041740 }
15051741
1506− out.push('>');
1507− out.push_str(ctx.nl());
1742+ // Image optimization: auto-add loading="lazy" and decoding="async"
1743+ if elem.kind == ElementKind::Image {
1744+ // SVG inlining: @image [inline] logo.svg
1745+ if elem.attrs.iter().any(|a| a.key == "inline")
1746+ && let Some(src) = &elem.argument
1747+ && src.ends_with(".svg")
1748+ && let Ok(svg_content) = std::fs::read_to_string(src)
1749+ {
1750+ // Close the tag we opened, then emit inline SVG instead
1751+ out.truncate(out.rfind('<').unwrap_or(0));
1752+ out.push_str(&ctx.indent());
1753+ out.push_str(svg_content.trim());
1754+ out.push_str(ctx.nl());
1755+ return;
1756+ }
1757+ // Responsive srcset: @image photo.jpg [responsive 400 800 1200]
1758+ let responsive_attr = elem.attrs.iter().find(|a| a.key == "responsive");
1759+ if let Some(resp) = responsive_attr
1760+ && let Some(ref sizes_str) = resp.value
1761+ {
1762+ let widths: Vec<&str> = sizes_str.split_whitespace().collect();
1763+ if !widths.is_empty() {
1764+ let src = elem.argument.as_deref().unwrap_or("");
1765+ if !src.is_empty() {
1766+ // Generate srcset with width descriptors
1767+ // Convention: file-{width}.ext (e.g., photo-400.jpg)
1768+ let dot_pos = src.rfind('.').unwrap_or(src.len());
1769+ let base = &src[..dot_pos];
1770+ let ext = &src[dot_pos..];
1771+ let mut srcset_parts = Vec::new();
1772+ for w in &widths {
1773+ srcset_parts.push(format!("{}-{}{} {}w", base, w, ext, w));
1774+ }
1775+ out.push_str(" srcset=\"");
1776+ out.push_str(&srcset_parts.join(", "));
1777+ out.push('"');
1778+ // Generate sizes attribute
1779+ let max_width = widths.last().unwrap_or(&"100vw");
1780+ out.push_str(&format!(
1781+ " sizes=\"(max-width: {}px) 100vw, {}px\"",
1782+ max_width, max_width
1783+ ));
1784+ }
1785+ }
1786+ }
1787+
1788+ // Auto image dimensions: read local image file to inject width/height + aspect-ratio
1789+ let has_width = elem.attrs.iter().any(|a| a.key == "width");
1790+ let has_height = elem.attrs.iter().any(|a| a.key == "height");
1791+ if (!has_width || !has_height)
1792+ && let Some(ref src) = elem.argument
1793+ && !src.starts_with("http://")
1794+ && !src.starts_with("https://")
1795+ && !src.starts_with("data:")
1796+ && let Some((w, h)) = read_image_dimensions(src)
1797+ {
1798+ // Intrinsic size attributes only when neither dimension is set in
1799+ // CSS; with one CSS dimension, a leftover intrinsic attribute for
1800+ // the other would distort the image (200 wide but 1000 tall).
1801+ if !has_width && !has_height {
1802+ out.push_str(&format!(" width=\"{}\" height=\"{}\"", w, h));
1803+ }
1804+ // Auto aspect-ratio to prevent CLS
1805+ if !elem.attrs.iter().any(|a| a.key == "aspect-ratio") {
1806+ out.push_str(&format!(" style=\"aspect-ratio:{}/{}\"", w, h));
1807+ }
1808+ }
1809+
1810+ // Smart image loading: first 3 images get fetchpriority="high" (above the fold),
1811+ // subsequent images get loading="lazy" + decoding="async"
1812+ ctx.image_count += 1;
1813+ if ctx.image_count <= 3 {
1814+ // Above-the-fold: eager loading with high priority
1815+ if !elem.attrs.iter().any(|a| a.key == "fetchpriority") {
1816+ out.push_str(" fetchpriority=\"high\"");
1817+ }
1818+ } else {
1819+ // Below-the-fold: lazy loading
1820+ if !elem.attrs.iter().any(|a| a.key == "loading") {
1821+ out.push_str(" loading=\"lazy\"");
1822+ }
1823+ if !elem.attrs.iter().any(|a| a.key == "decoding") {
1824+ out.push_str(" decoding=\"async\"");
1825+ }
1826+ }
1827+ }
1828+
1829+ out.push('>');
1830+ out.push_str(ctx.nl());
15081831}
15091832
15101833fn generate_text_segments(
@@ -1518,10 +1841,7 @@ fn generate_text_segments(
15181841 TextSegment::Plain(text) => out.push_str(&html_escape(text)),
15191842 TextSegment::Inline(elem) => {
15201843 let mut buf = String::new();
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;
1844+ generate_element(elem, None, &mut buf, styles, ctx);
15251845 out.push_str(buf.trim_end());
15261846 }
15271847 }
@@ -1534,97 +1854,143 @@ fn generate_text_segments(
15341854
15351855fn compute_class(
15361856 attrs: &[Attribute],
1537− site: &Site,
1857+ kind: &ElementKind,
1858+ parent_kind: Option<&ElementKind>,
15381859 styles: &mut StyleCollector,
1539− distinct: String,
1860+ has_overlay_children: bool,
15401861) -> Option<String> {
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);
1862+ let base = attrs_to_css(attrs, "", kind, parent_kind, has_overlay_children);
1863+
1864+ // Collect pseudo-state overrides
1865+ let mut pseudo = Vec::new();
1866+ for &(prefix, selector) in PSEUDO_PREFIXES {
1867+ let css = attrs_to_css(attrs, prefix, kind, parent_kind, has_overlay_children);
1868+ if !css.is_empty() {
1869+ pseudo.push((selector.to_string(), css));
15471870 }
15481871 }
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−}
15721872
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;");
1581− }
1582− if !site.root {
1583− css.push_str(layout_css(site.kind.layout(), site.inline));
1873+ // Auto-add ::-webkit-scrollbar pseudo for no-scrollbar attribute
1874+ if attrs.iter().any(|a| a.key == "no-scrollbar") {
1875+ pseudo.push((
1876+ "::-webkit-scrollbar".to_string(),
1877+ "display:none;".to_string(),
1878+ ));
15841879 }
1585− css.push_str(site.kind.css());
1586− css
1587−}
15881880
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;
1597− }
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;
1881+ // Collect nth:EXPR: dynamic pseudo selectors
1882+ let mut nth_prefixes: Vec<String> = Vec::new();
1883+ for attr in attrs {
1884+ if attr.key.starts_with("nth:") {
1885+ let rest = &attr.key[4..];
1886+ if let Some(colon_pos) = rest.find(':') {
1887+ let prefix = format!("nth:{}:", &rest[..colon_pos]);
1888+ if !nth_prefixes.contains(&prefix) {
1889+ nth_prefixes.push(prefix);
16121890 }
1613− _ => {}
16141891 }
16151892 }
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− })
1893+ }
1894+ for prefix in &nth_prefixes {
1895+ let expr = &prefix[4..prefix.len() - 1];
1896+ let selector = format!(":nth-child({})", expr);
1897+ let css = attrs_to_css(attrs, prefix, kind, parent_kind, has_overlay_children);
1898+ if !css.is_empty() {
1899+ pseudo.push((selector, css));
1900+ }
1901+ }
1902+
1903+ // Collect has(...): dynamic pseudo selectors
1904+ let mut has_prefixes: Vec<String> = Vec::new();
1905+ for attr in attrs {
1906+ if attr.key.starts_with("has(")
1907+ && let Some(close) = attr.key.find("):")
1908+ {
1909+ let prefix = format!("{}:", &attr.key[..close + 1]);
1910+ if !has_prefixes.contains(&prefix) {
1911+ has_prefixes.push(prefix);
1912+ }
1913+ }
1914+ }
1915+ for prefix in &has_prefixes {
1916+ let inner = &prefix[4..prefix.len() - 2]; // extract selector from has(selector):
1917+ let selector = format!(":has({})", inner);
1918+ let css = attrs_to_css(attrs, prefix, kind, parent_kind, has_overlay_children);
1919+ if !css.is_empty() {
1920+ pseudo.push((selector, css));
1921+ }
1922+ }
1923+
1924+ // Collect responsive overrides
1925+ let mut responsive = Vec::new();
1926+ for &(bp_name, _) in BREAKPOINTS {
1927+ let prefix = format!("{}:", bp_name);
1928+ let css = attrs_to_css(attrs, &prefix, kind, parent_kind, has_overlay_children);
1929+ if !css.is_empty() {
1930+ responsive.push((bp_name.to_string(), css));
1931+ }
1932+ }
1933+
1934+ // Collect container query overrides
1935+ let mut container = Vec::new();
1936+ for &(bp_name, _) in BREAKPOINTS {
1937+ let prefix = format!("cq-{}:", bp_name);
1938+ let css = attrs_to_css(attrs, &prefix, kind, parent_kind, has_overlay_children);
1939+ if !css.is_empty() {
1940+ container.push((bp_name.to_string(), css));
1941+ }
1942+ }
1943+
1944+ let dark = attrs_to_css(attrs, "dark:", kind, parent_kind, has_overlay_children);
1945+ let print = attrs_to_css(attrs, "print:", kind, parent_kind, has_overlay_children);
1946+ let motion_safe = attrs_to_css(attrs, "motion-safe:", kind, parent_kind, has_overlay_children);
1947+ let motion_reduce =
1948+ attrs_to_css(attrs, "motion-reduce:", kind, parent_kind, has_overlay_children);
1949+ let landscape = attrs_to_css(attrs, "landscape:", kind, parent_kind, has_overlay_children);
1950+ let portrait = attrs_to_css(attrs, "portrait:", kind, parent_kind, has_overlay_children);
1951+
1952+ // Dedupe: if a property is declared twice within a single rule, keep only
1953+ // the last occurrence (element-kind defaults are written before
1954+ // user attributes, so a user [list-style disc] correctly overrides the
1955+ // default list-style:none, and we don't need to ship both).
1956+ let base = dedupe_declarations(&base);
1957+ let pseudo: Vec<(String, String)> = pseudo
1958+ .into_iter()
1959+ .map(|(sel, css)| (sel, dedupe_declarations(&css)))
1960+ .collect();
1961+ let responsive: Vec<(String, String)> = responsive
1962+ .into_iter()
1963+ .map(|(bp, css)| (bp, dedupe_declarations(&css)))
1964+ .collect();
1965+ let dark = dedupe_declarations(&dark);
1966+ let print = dedupe_declarations(&print);
1967+ let motion_safe = dedupe_declarations(&motion_safe);
1968+ let motion_reduce = dedupe_declarations(&motion_reduce);
1969+ let landscape = dedupe_declarations(&landscape);
1970+ let portrait = dedupe_declarations(&portrait);
1971+ let container: Vec<(String, String)> = container
1972+ .into_iter()
1973+ .map(|(bp, css)| (bp, dedupe_declarations(&css)))
1974+ .collect();
1975+
1976+ styles.get_class(
1977+ base,
1978+ pseudo,
1979+ responsive,
1980+ dark,
1981+ print,
1982+ motion_safe,
1983+ motion_reduce,
1984+ landscape,
1985+ portrait,
1986+ container,
1987+ )
16211988}
16221989
16231990/// Dedupe CSS declarations within a single rule body: for any property
16241991/// declared more than once, keep only the last occurrence. Unparseable
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.
1992+/// segments (no `:`) are preserved as-is. Semicolons inside parentheses are
1993+/// treated as part of a value, not as declaration separators.
16281994fn dedupe_declarations(css: &str) -> String {
16291995 if css.is_empty() {
16301996 return String::new();
@@ -1639,26 +2005,8 @@ fn dedupe_declarations(css: &str) -> String {
16392005 let mut decls: Vec<(Option<String>, String)> = Vec::new();
16402006 let mut current = String::new();
16412007 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;
16462008 for ch in css.chars() {
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 == '(' {
2009+ if ch == '(' {
16622010 depth += 1;
16632011 current.push(ch);
16642012 } else if ch == ')' {
@@ -1740,592 +2088,993 @@ fn emit_class_attr(out: &mut String, gen_class: Option<&str>, user_class: Option
17402088// Attribute → CSS mapping
17412089// ---------------------------------------------------------------------------
17422090
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,
1755−}
2091+/// (htmlang prefix, CSS selector suffix)
2092+const PSEUDO_PREFIXES: &[(&str, &str)] = &[
2093+ ("hover:", ":hover"),
2094+ ("active:", ":active"),
2095+ ("focus:", ":focus"),
2096+ ("focus-visible:", ":focus-visible"),
2097+ ("focus-within:", ":focus-within"),
2098+ ("disabled:", ":disabled"),
2099+ ("checked:", ":checked"),
2100+ ("placeholder:", "::placeholder"),
2101+ ("first:", ":first-child"),
2102+ ("last:", ":last-child"),
2103+ ("odd:", ":nth-child(odd)"),
2104+ ("even:", ":nth-child(even)"),
2105+ ("before:", "::before"),
2106+ ("after:", "::after"),
2107+ ("selection:", "::selection"),
2108+ ("visited:", ":visited"),
2109+ ("empty:", ":empty"),
2110+ ("target:", ":target"),
2111+ ("valid:", ":valid"),
2112+ ("invalid:", ":invalid"),
2113+];
2114+const RESPONSIVE_PREFIXES: &[&str] = &["sm:", "md:", "lg:", "xl:", "2xl:"];
2115+const MEDIA_PREFIXES: &[&str] = &[
2116+ "dark:",
2117+ "print:",
2118+ "motion-safe:",
2119+ "motion-reduce:",
2120+ "landscape:",
2121+ "portrait:",
2122+];
2123+const CONTAINER_QUERY_PREFIXES: &[&str] = &["cq-sm:", "cq-md:", "cq-lg:", "cq-xl:", "cq-2xl:"];
17562124
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− }
2125+fn is_prefixed_attr(key: &str) -> bool {
2126+ PSEUDO_PREFIXES.iter().any(|&(p, _)| key.starts_with(p))
2127+ || RESPONSIVE_PREFIXES.iter().any(|p| key.starts_with(p))
2128+ || MEDIA_PREFIXES.iter().any(|p| key.starts_with(p))
2129+ || CONTAINER_QUERY_PREFIXES.iter().any(|p| key.starts_with(p))
2130+ || key.starts_with("nth:")
2131+ || key.starts_with("has(")
17692132}
17702133
1771−// ---------------------------------------------------------------------------
1772−// Direction: what a child's `fill` and `shrink` compile against
1773−// ---------------------------------------------------------------------------
2134+/// `display:flex;flex-direction:column;` — base layout for `@el` and every
2135+/// semantic wrapper that behaves like a column.
2136+const FLEX_COLUMN: &str = "display:flex;flex-direction:column;";
17742137
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−}
17812138
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−}
17932139
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−}
2140+fn attrs_to_css(
2141+ attrs: &[Attribute],
2142+ state_prefix: &str,
2143+ kind: &ElementKind,
2144+ parent_kind: Option<&ElementKind>,
2145+ has_overlay_children: bool,
2146+) -> String {
2147+ let mut css = String::new();
18132148
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;
1826− }
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));
1836− }
1837− }
1838− changes.sort_by_key(|(at, _)| at_order(at));
1839− Flow {
1840− base: Some(base),
1841− changes,
1842− class: None,
2149+ // Base element styles only for the default (non-state) pass
2150+ if state_prefix.is_empty() {
2151+ // Elements with @in-front / @behind children become positioning
2152+ // contexts. Pushed before user attrs so an explicit `position` wins
2153+ // via dedupe (only the last declaration of a property is kept).
2154+ if has_overlay_children {
2155+ css.push_str("position:relative;isolation:isolate;");
2156+ }
2157+ match kind {
2158+ ElementKind::Row => css.push_str("display:flex;flex-direction:row;"),
2159+ ElementKind::Column | ElementKind::El => css.push_str(FLEX_COLUMN),
2160+ ElementKind::Paragraph => css.push_str("margin:0;"),
2161+ ElementKind::Tag(spec) => css.push_str(spec.css),
2162+ _ => {}
18432163 }
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,
2164+ // Children of @carousel get scroll-snap-align and flex-shrink
2165+ if parent_kind.is_some_and(|k| k.is_tag("carousel")) {
2166+ css.push_str("scroll-snap-align:start;flex-shrink:0;");
18842167 }
18852168 }
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−}
1923−
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−}
19432169
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 {
2170+ for attr in attrs {
2171+ // Determine the effective key for this pass
2172+ let effective_key = if state_prefix.is_empty() {
2173+ if is_prefixed_attr(&attr.key) {
19532174 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− _ => {}
19792175 }
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;
2176+ attr.key.as_str()
2177+ } else {
2178+ match attr.key.strip_prefix(state_prefix) {
2179+ Some(k) => k,
2180+ None => continue,
20252181 }
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;
21492182 };
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− }
21592183
21602184 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− }
21662185
21672186 match effective_key {
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" => {
2187+ // Layout
2188+ "spacing" | "gap" => {
2189+ if let Some(v) = val {
2190+ push_css(&mut css, "gap", &css_px(v));
2191+ }
2192+ }
2193+ "padding" => {
2194+ if let Some(v) = val {
2195+ push_css(&mut css, "padding", &css_px_multi(v));
2196+ }
2197+ }
2198+ "padding-x" => {
2199+ if let Some(v) = val {
2200+ // Logical property covers both inline sides in one
2201+ // declaration; for symmetric values this is visually
2202+ // identical to padding-left/right in LTR and RTL.
2203+ push_css(&mut css, "padding-inline", &css_px(v));
2204+ }
2205+ }
2206+ "padding-y" => {
21722207 if let Some(v) = val {
2173− push_css(&mut css, "gap", &with_px("gap", v));
2208+ push_css(&mut css, "padding-block", &css_px(v));
2209+ }
2210+ }
2211+ "padding-top" => {
2212+ if let Some(v) = val {
2213+ push_css(&mut css, "padding-top", &css_px(v));
2214+ }
2215+ }
2216+ "padding-bottom" => {
2217+ if let Some(v) = val {
2218+ push_css(&mut css, "padding-bottom", &css_px(v));
2219+ }
2220+ }
2221+ "padding-left" => {
2222+ if let Some(v) = val {
2223+ push_css(&mut css, "padding-left", &css_px(v));
2224+ }
2225+ }
2226+ "padding-right" => {
2227+ if let Some(v) = val {
2228+ push_css(&mut css, "padding-right", &css_px(v));
21742229 }
21752230 }
21762231
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;
2232+ // Sizing
2233+ "width" => {
2234+ if let Some(v) = val {
2235+ match v {
2236+ "fill" => match parent_kind {
2237+ Some(ElementKind::Row) => {
2238+ push_css(&mut css, "flex", "1");
2239+ push_css(&mut css, "min-width", "0");
2240+ }
2241+ _ => push_css(&mut css, "width", "100%"),
2242+ },
2243+ "shrink" => push_css(&mut css, "flex-shrink", "0"),
2244+ _ => push_css(&mut css, "width", &css_px(v)),
2245+ }
21882246 }
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);
2247+ }
2248+ "height" => {
2249+ if let Some(v) = val {
2250+ match v {
2251+ "fill" => match parent_kind {
2252+ Some(ElementKind::Column) => {
2253+ push_css(&mut css, "flex", "1");
2254+ push_css(&mut css, "min-height", "0");
2255+ }
2256+ _ => push_css(&mut css, "height", "100%"),
2257+ },
2258+ "shrink" => push_css(&mut css, "flex-shrink", "0"),
2259+ _ => push_css(&mut css, "height", &css_px(v)),
22362260 }
22372261 }
2262+ }
2263+ "min-width" => {
22382264 if let Some(v) = val {
2239− push_css(&mut css, effective_key, &with_px(effective_key, v));
2265+ push_css(&mut css, "min-width", &css_px(v));
22402266 }
22412267 }
2242−
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");
2268+ "max-width" => {
2269+ if let Some(v) = val {
2270+ push_css(&mut css, "max-width", &css_px(v));
2271+ }
2272+ }
2273+ "min-height" => {
2274+ if let Some(v) = val {
2275+ push_css(&mut css, "min-height", &css_px(v));
2276+ }
22492277 }
2250− "center-y" => {
2251− push_css(&mut aligned, "margin-top", "auto");
2252− push_css(&mut aligned, "margin-bottom", "auto");
2278+ "max-height" => {
2279+ if let Some(v) = val {
2280+ push_css(&mut css, "max-height", &css_px(v));
2281+ }
22532282 }
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" => {}
22612283
2262− // Grid
2263− "grid-cols" | "grid-rows" if !lays_out_children => {}
2264− "grid-cols" | "grid-rows" => {
2284+ // Alignment
2285+ "center-x" => match parent_kind {
2286+ Some(ElementKind::Column) | Some(ElementKind::El) => {
2287+ push_css(&mut css, "align-self", "center");
2288+ }
2289+ _ => {
2290+ push_css(&mut css, "margin-left", "auto");
2291+ push_css(&mut css, "margin-right", "auto");
2292+ }
2293+ },
2294+ "center-y" => match parent_kind {
2295+ Some(ElementKind::Row) => push_css(&mut css, "align-self", "center"),
2296+ _ => {
2297+ push_css(&mut css, "margin-top", "auto");
2298+ push_css(&mut css, "margin-bottom", "auto");
2299+ }
2300+ },
2301+ "align-left" => match parent_kind {
2302+ Some(ElementKind::Column) | Some(ElementKind::El) => {
2303+ push_css(&mut css, "align-self", "flex-start");
2304+ }
2305+ _ => push_css(&mut css, "margin-right", "auto"),
2306+ },
2307+ "align-right" => match parent_kind {
2308+ Some(ElementKind::Column) | Some(ElementKind::El) => {
2309+ push_css(&mut css, "align-self", "flex-end");
2310+ }
2311+ _ => push_css(&mut css, "margin-left", "auto"),
2312+ },
2313+ "align-top" => match parent_kind {
2314+ Some(ElementKind::Row) => push_css(&mut css, "align-self", "flex-start"),
2315+ _ => push_css(&mut css, "margin-bottom", "auto"),
2316+ },
2317+ "align-bottom" => match parent_kind {
2318+ Some(ElementKind::Row) => push_css(&mut css, "align-self", "flex-end"),
2319+ _ => push_css(&mut css, "margin-top", "auto"),
2320+ },
2321+
2322+ // Style
2323+ "border" => {
22652324 if let Some(v) = val {
2266− let property = if effective_key == "grid-cols" {
2267− "grid-template-columns"
2325+ let parts: Vec<&str> = v.splitn(2, ' ').collect();
2326+ if parts.len() == 2 {
2327+ push_css(
2328+ &mut css,
2329+ "border",
2330+ &format!("{} solid {}", css_px(parts[0]), parts[1]),
2331+ );
22682332 } else {
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)),
2333+ push_css(
2334+ &mut css,
2335+ "border",
2336+ &format!("{} solid currentColor", css_px(parts[0])),
2337+ );
22742338 }
22752339 }
22762340 }
2277− "col-span" | "row-span" => {
2341+ "border-top" | "border-bottom" | "border-left" | "border-right" => {
22782342 if let Some(v) = val {
2279− let property = if effective_key == "col-span" {
2280− "grid-column"
2343+ let parts: Vec<&str> = v.splitn(2, ' ').collect();
2344+ if parts.len() == 2 {
2345+ push_css(
2346+ &mut css,
2347+ effective_key,
2348+ &format!("{} solid {}", css_px(parts[0]), parts[1]),
2349+ );
22812350 } else {
2282− "grid-row"
2351+ push_css(
2352+ &mut css,
2353+ effective_key,
2354+ &format!("{} solid currentColor", css_px(parts[0])),
2355+ );
2356+ }
2357+ }
2358+ }
2359+ "rounded" => {
2360+ if let Some(v) = val {
2361+ push_css(&mut css, "border-radius", &css_px(v));
2362+ }
2363+ }
2364+ "bold" => push_css(&mut css, "font-weight", "bold"),
2365+ "italic" => push_css(&mut css, "font-style", "italic"),
2366+ "underline" => push_css(&mut css, "text-decoration", "underline"),
2367+ "size" => {
2368+ if let Some(v) = val {
2369+ push_css(&mut css, "font-size", &css_px(v));
2370+ }
2371+ }
2372+ "font" => {
2373+ if let Some(v) = val {
2374+ // `font "Inter, sans-serif"` quotes a whole font stack so
2375+ // its commas don't split the attribute list.
2376+ let v = match v.strip_prefix('"').and_then(|v| v.strip_suffix('"')) {
2377+ Some(stack) if stack.contains(',') => stack,
2378+ _ => v,
22832379 };
2284− push_css(&mut css, property, &format!("span {}", v));
2380+ push_css(&mut css, "font-family", v);
22852381 }
22862382 }
22872383
2288− // CSS's `line-clamp` has no support yet without its
2289− // `-webkit-` fallback, which needs a box to clamp
2290− "line-clamp" => {
2384+ // Typography
2385+ "line-height" => {
22912386 if let Some(v) = val {
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");
2387+ push_css(&mut css, "line-height", &css_line_height(v));
2388+ }
2389+ }
2390+ "letter-spacing" => {
2391+ if let Some(v) = val {
2392+ push_css(&mut css, "letter-spacing", &css_px(v));
22962393 }
22972394 }
22982395
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) => {
2396+ // Overflow & positioning
2397+ "top" => {
2398+ if let Some(v) = val {
2399+ push_css(&mut css, "top", &css_px(v));
2400+ }
2401+ }
2402+ "right" => {
2403+ if let Some(v) = val {
2404+ push_css(&mut css, "right", &css_px(v));
2405+ }
2406+ }
2407+ "bottom" => {
2408+ if let Some(v) = val {
2409+ push_css(&mut css, "bottom", &css_px(v));
2410+ }
2411+ }
2412+ "left" => {
23052413 if let Some(v) = val {
2306− push_css(&mut css, key, &with_px(key, v));
2414+ push_css(&mut css, "left", &css_px(v));
23072415 }
23082416 }
23092417
2310− _ => {}
2311− }
2312− }
2418+ // Display & visibility
2419+ "hidden" => push_css(&mut css, "display", "none"),
23132420
2314− css.push_str(&aligned);
2315− css
2316−}
2421+ // Effects
2422+ "shadow" => {
2423+ if let Some(v) = val {
2424+ push_css(&mut css, "box-shadow", v);
2425+ }
2426+ }
23172427
2318−fn push_css(css: &mut String, prop: &str, value: &str) {
2319− css.push_str(prop);
2320− css.push(':');
2321− css.push_str(value);
2322− css.push(';');
2323−}
2428+ // Flow
2429+ "wrap" => push_css(&mut css, "flex-wrap", "wrap"),
2430+ "gap-x" => {
2431+ if let Some(v) = val {
2432+ push_css(&mut css, "column-gap", &css_px(v));
2433+ }
2434+ }
2435+ "gap-y" => {
2436+ if let Some(v) = val {
2437+ push_css(&mut css, "row-gap", &css_px(v));
2438+ }
2439+ }
2440+
2441+ // Grid
2442+ "grid" => {
2443+ push_css(&mut css, "display", "grid");
2444+ }
2445+ "grid-cols" => {
2446+ if let Some(v) = val {
2447+ if let Ok(n) = v.parse::<u32>() {
2448+ push_css(
2449+ &mut css,
2450+ "grid-template-columns",
2451+ &format!("repeat({},1fr)", n),
2452+ );
2453+ } else {
2454+ push_css(&mut css, "grid-template-columns", v);
2455+ }
2456+ }
2457+ }
2458+ "grid-rows" => {
2459+ if let Some(v) = val {
2460+ if let Ok(n) = v.parse::<u32>() {
2461+ push_css(
2462+ &mut css,
2463+ "grid-template-rows",
2464+ &format!("repeat({},1fr)", n),
2465+ );
2466+ } else {
2467+ push_css(&mut css, "grid-template-rows", v);
2468+ }
2469+ }
2470+ }
2471+ "col-span" => {
2472+ if let Some(v) = val {
2473+ push_css(&mut css, "grid-column", &format!("span {}", v));
2474+ }
2475+ }
2476+ "row-span" => {
2477+ if let Some(v) = val {
2478+ push_css(&mut css, "grid-row", &format!("span {}", v));
2479+ }
2480+ }
2481+
2482+ // CSS containment for rendering performance
2483+ "contain" => {
2484+ if let Some(v) = val {
2485+ push_css(&mut css, "contain", v);
2486+ } else {
2487+ push_css(&mut css, "contain", "layout style paint");
2488+ }
2489+ }
2490+ "content-visibility" => {
2491+ if let Some(v) = val {
2492+ push_css(&mut css, "content-visibility", v);
2493+ } else {
2494+ push_css(&mut css, "content-visibility", "auto");
2495+ }
2496+ }
2497+
2498+ // Outline (like border but doesn't affect layout)
2499+ "outline" => {
2500+ if let Some(v) = val {
2501+ let parts: Vec<&str> = v.splitn(2, ' ').collect();
2502+ if parts.len() == 2 {
2503+ push_css(
2504+ &mut css,
2505+ "outline",
2506+ &format!("{} solid {}", css_px(parts[0]), parts[1]),
2507+ );
2508+ } else {
2509+ push_css(
2510+ &mut css,
2511+ "outline",
2512+ &format!("{} solid currentColor", css_px(parts[0])),
2513+ );
2514+ }
2515+ }
2516+ }
2517+
2518+ // Logical properties (i18n-aware)
2519+ "padding-inline" => {
2520+ if let Some(v) = val {
2521+ push_css(&mut css, "padding-inline", &css_px_multi(v));
2522+ }
2523+ }
2524+ "padding-block" => {
2525+ if let Some(v) = val {
2526+ push_css(&mut css, "padding-block", &css_px_multi(v));
2527+ }
2528+ }
2529+ "margin-inline" => {
2530+ if let Some(v) = val {
2531+ push_css(&mut css, "margin-inline", &css_px_multi(v));
2532+ }
2533+ }
2534+ "margin-block" => {
2535+ if let Some(v) = val {
2536+ push_css(&mut css, "margin-block", &css_px_multi(v));
2537+ }
2538+ }
2539+
2540+ // Logical property start/end variants
2541+ "padding-inline-start"
2542+ | "padding-inline-end"
2543+ | "padding-block-start"
2544+ | "padding-block-end"
2545+ | "margin-inline-start"
2546+ | "margin-inline-end"
2547+ | "margin-block-start"
2548+ | "margin-block-end" => {
2549+ if let Some(v) = val {
2550+ push_css(&mut css, effective_key, &css_px(v));
2551+ }
2552+ }
2553+
2554+ // Logical inset
2555+ "inset-inline" | "inset-block" => {
2556+ if let Some(v) = val {
2557+ push_css(&mut css, effective_key, &css_px_multi(v));
2558+ }
2559+ }
2560+ "inset-inline-start" | "inset-inline-end" | "inset-block-start" | "inset-block-end" => {
2561+ if let Some(v) = val {
2562+ push_css(&mut css, effective_key, &css_px(v));
2563+ }
2564+ }
2565+
2566+ // Logical border
2567+ "border-inline"
2568+ | "border-block"
2569+ | "border-inline-start"
2570+ | "border-inline-end"
2571+ | "border-block-start"
2572+ | "border-block-end" => {
2573+ if let Some(v) = val {
2574+ push_css(&mut css, effective_key, v);
2575+ }
2576+ }
2577+
2578+ // Logical border-radius
2579+ "border-start-start-radius"
2580+ | "border-start-end-radius"
2581+ | "border-end-start-radius"
2582+ | "border-end-end-radius" => {
2583+ if let Some(v) = val {
2584+ push_css(&mut css, effective_key, &css_px(v));
2585+ }
2586+ }
2587+
2588+ // Logical scroll margins & padding
2589+ "scroll-margin-inline"
2590+ | "scroll-margin-block"
2591+ | "scroll-padding-inline"
2592+ | "scroll-padding-block" => {
2593+ if let Some(v) = val {
2594+ push_css(&mut css, effective_key, &css_px_multi(v));
2595+ }
2596+ }
2597+
2598+ // Logical sizing
2599+ "inline-size" | "block-size" | "min-inline-size" | "max-inline-size"
2600+ | "min-block-size" | "max-block-size" => {
2601+ if let Some(v) = val {
2602+ push_css(&mut css, effective_key, &css_px(v));
2603+ }
2604+ }
2605+
2606+ // Margin
2607+ "margin" => {
2608+ if let Some(v) = val {
2609+ push_css(&mut css, "margin", &css_px_multi(v));
2610+ }
2611+ }
2612+ "margin-x" => {
2613+ if let Some(v) = val {
2614+ push_css(&mut css, "margin-inline", &css_px(v));
2615+ }
2616+ }
2617+ "margin-y" => {
2618+ if let Some(v) = val {
2619+ push_css(&mut css, "margin-block", &css_px(v));
2620+ }
2621+ }
2622+
2623+ // Container queries
2624+ "container" => {
2625+ push_css(&mut css, "container-type", "inline-size");
2626+ }
2627+
2628+ // Inset (shorthand for top/right/bottom/left)
2629+ "inset" => {
2630+ if let Some(v) = val {
2631+ push_css(&mut css, "inset", &css_px(v));
2632+ }
2633+ }
2634+
2635+ // Table
2636+ "border-spacing" => {
2637+ if let Some(v) = val {
2638+ push_css(&mut css, "border-spacing", &css_px(v));
2639+ }
2640+ }
2641+
2642+ // Text decoration
2643+ "text-decoration-thickness" => {
2644+ if let Some(v) = val {
2645+ push_css(&mut css, "text-decoration-thickness", &css_px(v));
2646+ }
2647+ }
2648+ "text-underline-offset" => {
2649+ if let Some(v) = val {
2650+ push_css(&mut css, "text-underline-offset", &css_px(v));
2651+ }
2652+ }
2653+
2654+ // Multi-column
2655+ "column-width" => {
2656+ if let Some(v) = val {
2657+ push_css(&mut css, "column-width", &css_px(v));
2658+ }
2659+ }
2660+
2661+ // New CSS properties
2662+ "column-gap" => {
2663+ if let Some(v) = val {
2664+ push_css(&mut css, "column-gap", &css_px(v));
2665+ }
2666+ }
2667+ "text-indent" => {
2668+ if let Some(v) = val {
2669+ push_css(&mut css, "text-indent", &css_px(v));
2670+ }
2671+ }
2672+ "flex-basis" => {
2673+ if let Some(v) = val {
2674+ push_css(&mut css, "flex-basis", &css_px(v));
2675+ }
2676+ }
2677+ "scroll-margin" => {
2678+ if let Some(v) = val {
2679+ push_css(&mut css, "scroll-margin", &css_px(v));
2680+ }
2681+ }
2682+ "scroll-margin-top"
2683+ | "scroll-margin-bottom"
2684+ | "scroll-margin-left"
2685+ | "scroll-margin-right" => {
2686+ if let Some(v) = val {
2687+ push_css(&mut css, effective_key, &css_px(v));
2688+ }
2689+ }
2690+ "scroll-padding" => {
2691+ if let Some(v) = val {
2692+ push_css(&mut css, "scroll-padding", &css_px(v));
2693+ }
2694+ }
2695+ "scroll-padding-top"
2696+ | "scroll-padding-bottom"
2697+ | "scroll-padding-left"
2698+ | "scroll-padding-right" => {
2699+ if let Some(v) = val {
2700+ push_css(&mut css, effective_key, &css_px(v));
2701+ }
2702+ }
2703+
2704+ "content" => {
2705+ if let Some(v) = val {
2706+ // Wrap in quotes if not already quoted and not a CSS keyword
2707+ if v.starts_with('"')
2708+ || v.starts_with('\'')
2709+ || v == "none"
2710+ || v == "normal"
2711+ || v.starts_with("attr(")
2712+ || v.starts_with("counter(")
2713+ {
2714+ push_css(&mut css, "content", v);
2715+ } else {
2716+ push_css(&mut css, "content", &format!("\"{}\"", v));
2717+ }
2718+ }
2719+ }
2720+
2721+ // --- CSS Shorthands ---
2722+ "truncate" => {
2723+ push_css(&mut css, "overflow", "hidden");
2724+ push_css(&mut css, "text-overflow", "ellipsis");
2725+ push_css(&mut css, "white-space", "nowrap");
2726+ }
2727+ "line-clamp" => {
2728+ if let Some(v) = val {
2729+ push_css(&mut css, "display", "-webkit-box");
2730+ push_css(&mut css, "-webkit-line-clamp", v);
2731+ push_css(&mut css, "-webkit-box-orient", "vertical");
2732+ push_css(&mut css, "overflow", "hidden");
2733+ }
2734+ }
2735+ "blur" => {
2736+ if let Some(v) = val {
2737+ push_css(&mut css, "filter", &format!("blur({})", css_px(v)));
2738+ }
2739+ }
2740+ "backdrop-blur" => {
2741+ if let Some(v) = val {
2742+ push_css(&mut css, "backdrop-filter", &format!("blur({})", css_px(v)));
2743+ }
2744+ }
2745+ "no-scrollbar" => {
2746+ push_css(&mut css, "scrollbar-width", "none");
2747+ push_css(&mut css, "-ms-overflow-style", "none");
2748+ }
2749+ "skeleton" => {
2750+ push_css(
2751+ &mut css,
2752+ "background",
2753+ "linear-gradient(90deg,#e5e7eb 25%,#f3f4f6 50%,#e5e7eb 75%)",
2754+ );
2755+ push_css(&mut css, "background-size", "200% 100%");
2756+ push_css(
2757+ &mut css,
2758+ "animation",
2759+ "hl-skeleton 1.5s ease-in-out infinite",
2760+ );
2761+ }
2762+ "gradient" => {
2763+ if let Some(v) = val {
2764+ // Parse: "from to [angle]" or "color1 color2 [angle]"
2765+ let parts: Vec<&str> = v.split_whitespace().collect();
2766+ let bg = if parts.len() >= 3
2767+ && (parts[2].ends_with("deg")
2768+ || parts[2].ends_with("turn")
2769+ || parts[2].ends_with("rad"))
2770+ {
2771+ format!("linear-gradient({},{},{})", parts[2], parts[0], parts[1])
2772+ } else if parts.len() >= 2 {
2773+ format!("linear-gradient({},{})", parts[0], parts[1])
2774+ } else {
2775+ format!("linear-gradient({},transparent)", parts[0])
2776+ };
2777+ push_css(&mut css, "background", &bg);
2778+ }
2779+ }
2780+
2781+ // Critical CSS hint — not CSS, handled elsewhere
2782+ "critical" => {}
2783+
2784+ // Identity and HTML passthrough — not CSS
2785+ "id" | "class" => {}
2786+ "type" | "placeholder" | "name" | "value" | "disabled" | "required" | "checked"
2787+ | "for" | "action" | "method" | "autocomplete" | "min" | "max" | "step" | "pattern"
2788+ | "maxlength" | "rows" | "cols" | "multiple" | "alt" | "role" | "tabindex"
2789+ | "title" | "controls" | "autoplay" | "loop" | "muted" | "playsinline" | "poster"
2790+ | "preload" | "loading" | "decoding" | "ordered" | "src" | "open" | "novalidate"
2791+ | "low" | "high" | "optimum" | "colspan" | "rowspan" | "scope" | "inline"
2792+ | "responsive" | "datetime" | "media" | "sizes" | "srcset" | "cite" | "list"
2793+ | "sandbox" | "allow" | "allowfullscreen" | "referrerpolicy" | "formaction"
2794+ | "formmethod" | "formtarget" | "target" | "autofocus" => {}
2795+
2796+ // Any other standard CSS property is copied through, with `px`
2797+ // added to bare numbers where the property takes a length.
2798+ key if crate::vocab::is_css_property(key) && !crate::vocab::is_html_passthrough(key) => {
2799+ if let Some(v) = val {
2800+ if crate::vocab::is_length_property(key) {
2801+ push_css(&mut css, key, &css_px_multi(v));
2802+ } else {
2803+ push_css(&mut css, key, v);
2804+ }
2805+ }
2806+ }
2807+
2808+ _ => {}
2809+ }
2810+ }
2811+
2812+ css
2813+}
2814+
2815+fn push_css(css: &mut String, prop: &str, value: &str) {
2816+ css.push_str(prop);
2817+ css.push(':');
2818+ css.push_str(value);
2819+ css.push(';');
2820+}
2821+
2822+/// Known CSS units — if a value ends with one, skip appending `px`.
2823+/// Format a length value: a bare number gets `px` appended; anything else
2824+/// (values with units, keywords like `auto`, functions like `calc(...)`) is
2825+/// passed through unchanged.
2826+fn css_px(value: &str) -> String {
2827+ let v = value.trim();
2828+ if v == "0" {
2829+ return "0".to_string();
2830+ }
2831+ let is_bare_number = !v.is_empty()
2832+ && v.bytes().all(|b| b.is_ascii_digit() || matches!(b, b'.' | b'-' | b'+'))
2833+ && v.parse::<f64>().is_ok();
2834+ if is_bare_number {
2835+ format!("{}px", v)
2836+ } else {
2837+ v.to_string()
2838+ }
2839+}
2840+
2841+/// Rewrite literal values that match a declared CSS custom property (from
2842+/// `@theme` or `@let --name value`) to `var(--name)` references. Matches are
2843+/// anchored to CSS value boundaries so e.g. `#3b82f6` inside a longer hex or
2844+/// inside an identifier is not replaced. The `:root` block is emitted before
2845+/// this call runs, so its declarations are not affected.
2846+fn substitute_css_vars(css: &str, vars: &[(String, String)]) -> String {
2847+ if css.is_empty() || vars.is_empty() {
2848+ return css.to_string();
2849+ }
2850+ // Prefer longer values first so that if two vars share a prefix, the
2851+ // longer (more specific) match wins.
2852+ let mut pairs: Vec<(&str, String)> = vars
2853+ .iter()
2854+ .filter(|(name, value)| name.starts_with("--") && !value.is_empty())
2855+ .map(|(name, value)| (value.as_str(), format!("var({})", name)))
2856+ .collect();
2857+ pairs.sort_by_key(|(v, _)| std::cmp::Reverse(v.len()));
2858+ if pairs.is_empty() {
2859+ return css.to_string();
2860+ }
2861+
2862+ let is_boundary_before = |b: Option<u8>| match b {
2863+ None => true,
2864+ Some(c) => matches!(c, b':' | b' ' | b',' | b'(' | b';' | b'{' | b'\n' | b'\t'),
2865+ };
2866+ let is_boundary_after = |b: Option<u8>| match b {
2867+ None => true,
2868+ Some(c) => matches!(c, b';' | b'}' | b',' | b' ' | b')' | b'\n' | b'\t'),
2869+ };
2870+
2871+ let bytes = css.as_bytes();
2872+ let mut out = String::with_capacity(css.len());
2873+ let mut i = 0;
2874+ let mut prev: Option<u8> = None;
2875+ // Only declaration values are rewritten — never selectors or at-rule
2876+ // preludes such as `@media (min-width:768px)`. `blocks` records, for
2877+ // each open `{`, whether it holds declarations (a style rule) or nested
2878+ // rules (an at-rule like `@media` / `@layer`).
2879+ let mut blocks: Vec<bool> = Vec::new();
2880+ let mut prelude_start = 0;
2881+ let mut in_value = false;
2882+ while i < bytes.len() {
2883+ match bytes[i] {
2884+ b'{' => {
2885+ let prelude = css[prelude_start..i].trim_start();
2886+ blocks.push(!prelude.starts_with('@'));
2887+ in_value = false;
2888+ prelude_start = i + 1;
2889+ }
2890+ b'}' => {
2891+ blocks.pop();
2892+ in_value = false;
2893+ prelude_start = i + 1;
2894+ }
2895+ b';' => {
2896+ in_value = false;
2897+ prelude_start = i + 1;
2898+ }
2899+ b':' if blocks.last() == Some(&true) => in_value = true,
2900+ _ => {}
2901+ }
2902+ if in_value && is_boundary_before(prev) {
2903+ let mut matched = false;
2904+ for (val, repl) in &pairs {
2905+ let vb = val.as_bytes();
2906+ if i + vb.len() <= bytes.len() && &bytes[i..i + vb.len()] == vb {
2907+ let next = bytes.get(i + vb.len()).copied();
2908+ if is_boundary_after(next) {
2909+ out.push_str(repl);
2910+ prev = repl.as_bytes().last().copied();
2911+ i += vb.len();
2912+ matched = true;
2913+ break;
2914+ }
2915+ }
2916+ }
2917+ if matched {
2918+ continue;
2919+ }
2920+ }
2921+ // Advance by one UTF-8 code point.
2922+ let start = i;
2923+ i += 1;
2924+ while i < bytes.len() && (bytes[i] & 0xC0) == 0x80 {
2925+ i += 1;
2926+ }
2927+ out.push_str(&css[start..i]);
2928+ prev = bytes.get(i - 1).copied();
2929+ }
2930+ out
2931+}
2932+
2933+/// Scan generated CSS for literal property values that repeat often enough
2934+/// that substituting them with an auto-named custom property would reduce
2935+/// total byte count. Returns the rewritten CSS and any new vars that should
2936+/// be appended to `:root`.
2937+///
2938+/// The algorithm only promotes a value if it strictly saves bytes after
2939+/// accounting for the `--xN:value;` declaration overhead plus the
2940+/// `var(--xN)` reference cost at each call site. Values that are already
2941+/// `var(...)` references or contain `var(` calls are skipped so we never
2942+/// nest references. Names avoid collisions with `existing_vars`.
2943+fn auto_extract_repeats(
2944+ css: &str,
2945+ existing_vars: &[(String, String)],
2946+) -> (String, Vec<(String, String)>) {
2947+ if css.is_empty() {
2948+ return (css.to_string(), Vec::new());
2949+ }
2950+ // Count occurrences of each distinct property value (the text between
2951+ // `:` and the next `;` or `}` at the top level of a declaration block,
2952+ // ignoring balanced parentheses so that e.g. `rgba(...)` stays intact).
2953+ let bytes = css.as_bytes();
2954+ let mut counts: HashMap<String, usize> = HashMap::new();
2955+ let mut depth: i32 = 0;
2956+ let mut i = 0;
2957+ while i < bytes.len() {
2958+ match bytes[i] {
2959+ b'{' => {
2960+ depth += 1;
2961+ i += 1;
2962+ continue;
2963+ }
2964+ b'}' => {
2965+ if depth > 0 {
2966+ depth -= 1;
2967+ }
2968+ i += 1;
2969+ continue;
2970+ }
2971+ _ => {}
2972+ }
2973+ if depth > 0 && bytes[i] == b':' {
2974+ // Skip past `:` then walk to the terminator.
2975+ let start = i + 1;
2976+ let mut end = start;
2977+ let mut pdepth = 0i32;
2978+ while end < bytes.len() {
2979+ match bytes[end] {
2980+ b'(' => pdepth += 1,
2981+ b')' if pdepth > 0 => pdepth -= 1,
2982+ b';' | b'}' if pdepth == 0 => break,
2983+ b'{' if pdepth == 0 => break,
2984+ _ => {}
2985+ }
2986+ end += 1;
2987+ }
2988+ let val = css[start..end].trim();
2989+ if !val.is_empty() && !val.starts_with("var(") && !val.contains("var(") {
2990+ *counts.entry(val.to_string()).or_default() += 1;
2991+ }
2992+ i = end;
2993+ continue;
2994+ }
2995+ i += 1;
2996+ }
2997+
2998+ // Decide which values are worth extracting. A value of length L appearing
2999+ // N times costs N*L bytes inline; promoting it costs (L + 6) for the
3000+ // `--hK:V;` declaration plus N * ref_len for the call sites. We estimate
3001+ // ref_len optimistically as `var(--h0)` (9 bytes) and fall back to 10 for
3002+ // two-digit indices, which only affects very large extraction counts.
3003+ let existing: std::collections::HashSet<&str> =
3004+ existing_vars.iter().map(|(n, _)| n.as_str()).collect();
3005+ let mut candidates: Vec<(String, usize)> =
3006+ counts.into_iter().filter(|(_, n)| *n >= 2).collect();
3007+ // Stable, deterministic ordering — longest values first, tiebreak by text.
3008+ candidates.sort_by(|a, b| b.0.len().cmp(&a.0.len()).then_with(|| a.0.cmp(&b.0)));
3009+
3010+ let mut extracted: Vec<(String, String)> = Vec::new();
3011+ let mut next_idx: usize = 0;
3012+ for (value, n) in candidates {
3013+ let l = value.len();
3014+ // Allocate the next unused `--hN` name.
3015+ let (name, ref_len) = loop {
3016+ let candidate = format!("--h{}", next_idx);
3017+ next_idx += 1;
3018+ let rl = candidate.len() + 6; // `var(` + name + `)`
3019+ if !existing.contains(candidate.as_str())
3020+ && !extracted.iter().any(|(n, _)| *n == candidate)
3021+ {
3022+ break (candidate, rl);
3023+ }
3024+ };
3025+ // Skip if promotion would not strictly reduce byte count.
3026+ // Before: n * l bytes. After: (l + name.len() + 2) for the :root
3027+ // declaration (`<name>:<value>;`) plus n * ref_len for the sites.
3028+ let decl_overhead = l + name.len() + 2;
3029+ let before = n * l;
3030+ let after = decl_overhead + n * ref_len;
3031+ if after < before {
3032+ extracted.push((name, value));
3033+ } else {
3034+ // Rewind the index so the next value can reuse this slot.
3035+ next_idx -= 1;
3036+ }
3037+ }
3038+
3039+ if extracted.is_empty() {
3040+ return (css.to_string(), Vec::new());
3041+ }
3042+ let new_css = substitute_css_vars(css, &extracted);
3043+ (new_css, extracted)
3044+}
3045+
3046+/// Format a `line-height` value. CSS accepts either a unitless multiplier
3047+/// (e.g. `1.5`) or a length (e.g. `24px`). Plain integers in htmlang source
3048+/// are ambiguous: `[line-height 24]` was historically emitted as `24` (which
3049+/// CSS interprets as 24× font-size — almost never what anyone wants). Treat
3050+/// integers ≥ 2 as pixel lengths; anything with a decimal, an existing unit,
3051+/// or the value `0`/`1` passes through unchanged.
3052+fn css_line_height(value: &str) -> String {
3053+ let v = value.trim();
3054+ if v == "0" || v == "1" {
3055+ return v.to_string();
3056+ }
3057+ // Plain integer — treat as pixel length. Decimals, units, keywords and
3058+ // functions pass through.
3059+ if !v.is_empty() && v.chars().all(|c| c.is_ascii_digit()) {
3060+ return format!("{}px", v);
3061+ }
3062+ v.to_string()
3063+}
3064+
3065+/// Format multiple space-separated values, each getting px if needed.
3066+fn css_px_multi(value: &str) -> String {
3067+ value
3068+ .split_whitespace()
3069+ .map(css_px)
3070+ .collect::<Vec<_>>()
3071+ .join(" ")
3072+}
23243073
23253074fn extract_id_class(attrs: &[Attribute]) -> (Option<String>, Option<String>) {
23263075 let mut id = None;
23273076 let mut class = None;
2328− for attr in attrs.iter().filter(|a| a.html) {
3077+ for attr in attrs {
23293078 match attr.key.as_str() {
23303079 "id" => id = attr.value.clone(),
23313080 "class" => class = attr.value.clone(),
@@ -2335,6 +3084,153 @@ fn extract_id_class(attrs: &[Attribute]) -> (Option<String>, Option<String>) {
23353084 (id, class)
23363085}
23373086
3087+/// Read image dimensions from a local file by parsing the header bytes.
3088+/// Supports PNG, JPEG, GIF, WebP, AVIF, and SVG.
3089+fn read_image_dimensions(path: &str) -> Option<(u32, u32)> {
3090+ // SVG: parse as text for viewBox/width/height attributes
3091+ if path.ends_with(".svg") || path.ends_with(".SVG") {
3092+ let text = std::fs::read_to_string(path).ok()?;
3093+ return read_svg_dimensions(&text);
3094+ }
3095+
3096+ let data = std::fs::read(path).ok()?;
3097+ if data.len() < 12 {
3098+ return None;
3099+ }
3100+
3101+ // PNG: 8-byte signature, then IHDR chunk with width/height at bytes 16-23
3102+ if data.len() >= 24 && data.starts_with(b"\x89PNG\r\n\x1a\n") {
3103+ let w = u32::from_be_bytes([data[16], data[17], data[18], data[19]]);
3104+ let h = u32::from_be_bytes([data[20], data[21], data[22], data[23]]);
3105+ return Some((w, h));
3106+ }
3107+
3108+ // GIF: "GIF87a" or "GIF89a", width/height at bytes 6-9 (little-endian)
3109+ if data.starts_with(b"GIF87a") || data.starts_with(b"GIF89a") {
3110+ let w = u16::from_le_bytes([data[6], data[7]]) as u32;
3111+ let h = u16::from_le_bytes([data[8], data[9]]) as u32;
3112+ return Some((w, h));
3113+ }
3114+
3115+ // JPEG: scan for SOF0/SOF2 marker (0xFF 0xC0 or 0xFF 0xC2)
3116+ if data.starts_with(b"\xff\xd8") {
3117+ let mut i = 2;
3118+ while i + 9 < data.len() {
3119+ if data[i] != 0xFF {
3120+ i += 1;
3121+ continue;
3122+ }
3123+ let marker = data[i + 1];
3124+ if marker == 0xC0 || marker == 0xC2 {
3125+ let h = u16::from_be_bytes([data[i + 5], data[i + 6]]) as u32;
3126+ let w = u16::from_be_bytes([data[i + 7], data[i + 8]]) as u32;
3127+ return Some((w, h));
3128+ }
3129+ if i + 3 < data.len() {
3130+ let len = u16::from_be_bytes([data[i + 2], data[i + 3]]) as usize;
3131+ i += 2 + len;
3132+ } else {
3133+ break;
3134+ }
3135+ }
3136+ }
3137+
3138+ // WebP: "RIFF" ... "WEBP", VP8 header at byte 20
3139+ if data.len() >= 30 && &data[..4] == b"RIFF" && &data[8..12] == b"WEBP" {
3140+ if &data[12..16] == b"VP8 " && data.len() >= 30 {
3141+ let w = u16::from_le_bytes([data[26], data[27]]) as u32 & 0x3FFF;
3142+ let h = u16::from_le_bytes([data[28], data[29]]) as u32 & 0x3FFF;
3143+ return Some((w, h));
3144+ }
3145+ if &data[12..16] == b"VP8L" && data.len() >= 25 && data[21] == 0x2F {
3146+ let bits = u32::from_le_bytes([data[22], data[23], data[24], data[25]]);
3147+ let w = (bits & 0x3FFF) + 1;
3148+ let h = ((bits >> 14) & 0x3FFF) + 1;
3149+ return Some((w, h));
3150+ }
3151+ }
3152+
3153+ // AVIF: ISOBMFF container with "ftyp" box containing "avif"/"avis" brand,
3154+ // then "ispe" box with width/height
3155+ if data.len() >= 12 && &data[4..8] == b"ftyp" {
3156+ let brand = &data[8..12];
3157+ if brand == b"avif" || brand == b"avis" || brand == b"mif1" {
3158+ return read_avif_dimensions(&data);
3159+ }
3160+ }
3161+
3162+ None
3163+}
3164+
3165+/// Parse SVG viewBox or width/height attributes to get dimensions.
3166+fn read_svg_dimensions(text: &str) -> Option<(u32, u32)> {
3167+ // Try viewBox first: viewBox="minX minY width height"
3168+ if let Some(vb_start) = text.find("viewBox=\"") {
3169+ let rest = &text[vb_start + 9..];
3170+ if let Some(end) = rest.find('"') {
3171+ let parts: Vec<&str> = rest[..end].split_whitespace().collect();
3172+ if parts.len() == 4
3173+ && let (Ok(w), Ok(h)) = (parts[2].parse::<f64>(), parts[3].parse::<f64>())
3174+ && w > 0.0
3175+ && h > 0.0
3176+ {
3177+ return Some((w.round() as u32, h.round() as u32));
3178+ }
3179+ }
3180+ }
3181+ // Fall back to width/height attributes on <svg>
3182+ let svg_tag = text.find("<svg")?;
3183+ let tag_end = text[svg_tag..].find('>')? + svg_tag;
3184+ let tag = &text[svg_tag..tag_end];
3185+ let w = extract_svg_attr(tag, "width")?;
3186+ let h = extract_svg_attr(tag, "height")?;
3187+ Some((w, h))
3188+}
3189+
3190+fn extract_svg_attr(tag: &str, attr: &str) -> Option<u32> {
3191+ let needle = format!("{}=\"", attr);
3192+ let start = tag.find(&needle)? + needle.len();
3193+ let rest = &tag[start..];
3194+ let end = rest.find('"')?;
3195+ let val = rest[..end].trim_end_matches("px");
3196+ val.parse::<f64>().ok().map(|v| v.round() as u32)
3197+}
3198+
3199+/// Parse AVIF (ISOBMFF) container to find ispe box with image dimensions.
3200+fn read_avif_dimensions(data: &[u8]) -> Option<(u32, u32)> {
3201+ // Walk ISOBMFF boxes looking for "ispe" (image spatial extents)
3202+ let mut i = 0;
3203+ while i + 8 <= data.len() {
3204+ let box_size =
3205+ u32::from_be_bytes([data[i], data[i + 1], data[i + 2], data[i + 3]]) as usize;
3206+ let box_type = &data[i + 4..i + 8];
3207+ if box_size < 8 {
3208+ break;
3209+ }
3210+ let box_end = (i + box_size).min(data.len());
3211+ // ispe box: 4 bytes version/flags + 4 bytes width + 4 bytes height
3212+ if box_type == b"ispe" && box_end >= i + 20 {
3213+ let w = u32::from_be_bytes([data[i + 12], data[i + 13], data[i + 14], data[i + 15]]);
3214+ let h = u32::from_be_bytes([data[i + 16], data[i + 17], data[i + 18], data[i + 19]]);
3215+ return Some((w, h));
3216+ }
3217+ // Recurse into container boxes (meta, iprp, ipco)
3218+ if matches!(
3219+ box_type,
3220+ b"meta" | b"iprp" | b"ipco" | b"moov" | b"trak" | b"mdia"
3221+ ) {
3222+ let header_size = if box_type == b"meta" { 12 } else { 8 };
3223+ if i + header_size < box_end
3224+ && let Some(dims) = read_avif_dimensions(&data[i + header_size..box_end])
3225+ {
3226+ return Some(dims);
3227+ }
3228+ }
3229+ i = box_end;
3230+ }
3231+ None
3232+}
3233+
23383234fn html_escape(s: &str) -> String {
23393235 s.replace('&', "&")
23403236 .replace('<', "<")
@@ -2450,30 +3346,43 @@ fn vlq_encode(value: i64, out: &mut String) {
24503346 }
24513347}
24523348
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()));
3349+
3350+/// Does the tree contain the table element `name` (e.g. `"main"`)?
3351+fn has_tag(nodes: &[Node], name: &str) -> bool {
3352+ nodes.iter().any(|node| match node {
3353+ Node::Element(elem) => elem.kind.is_tag(name) || has_tag(&elem.children, name),
3354+ _ => false,
3355+ })
3356+}
3357+
3358+/// Collect unique external domains from generated HTML for DNS prefetch hints.
3359+fn collect_dns_prefetch(html: &str, dev: bool) -> String {
3360+ let mut domains = Vec::new();
3361+ let mut rest = html;
3362+ while let Some(pos) = rest.find("https://") {
3363+ let start = pos + 8; // skip "https://"
3364+ rest = &rest[start..];
3365+ let end = rest
3366+ .find(['/', '"', '\'', ' ', '>', ')'])
3367+ .unwrap_or(rest.len());
3368+ let domain = &rest[..end];
3369+ if !domain.is_empty() && domain.contains('.') && !domains.contains(&domain.to_string()) {
3370+ domains.push(domain.to_string());
3371+ }
24783372 }
3373+ let mut out = String::new();
3374+ for domain in &domains {
3375+ if dev {
3376+ out.push_str(&format!(
3377+ "<link rel=\"dns-prefetch\" href=\"//{}\">\n",
3378+ domain
3379+ ));
3380+ } else {
3381+ out.push_str(&format!(
3382+ "<link rel=\"dns-prefetch\" href=\"//{}\">",
3383+ domain
3384+ ));
3385+ }
3386+ }
3387+ out
24793388}