@@ -1,8 +1,7 @@
1use std::collections::HashMap;
1use std::collections::HashMap;
2−use std::hash::Hash;
2+use std::hash::{Hash, Hasher};
4use crate::ast::*;
4use crate::ast::*;
5−use crate::vocab::with_px;
7// ---------------------------------------------------------------------------
6// ---------------------------------------------------------------------------
8// Style collector: deduplicates CSS and assigns class names
7// Style collector: deduplicates CSS and assigns class names
@@ -17,315 +16,56 @@ const BREAKPOINTS: &[(&str, &str)] = &[
17 ("2xl", "1536px"),
16 ("2xl", "1536px"),
20−/// The prefix of every generated class (`hl-2k9xq0m`), which keeps them
19+/// Generate short CSS class names: a..z, then aa..a9, ba..b9, ..., z9, then
21−/// out of the author's own class names.
20+/// aaa, ... The first character is always a letter; later ones are drawn from
22−pub const CLASS_PREFIX: &str = "hl-";
21+/// [a-z0-9]. The mapping is a bijection, so distinct indices never collide.
23−
22+pub(crate) fn short_class_name(idx: usize) -> String {
24−/// How many base-36 digits a class's name has after `hl-`: 7, about 36
23+ const REST: &[u8] = b"abcdefghijklmnopqrstuvwxyz0123456789";
25−/// bits of its style's hash, so a site with 10,000 different styles has
24+ // Find the name length: 26 names of length 1, 26*36 of length 2, ...
26−/// odds of about 6 in 10,000 that two of them share a name, which
25+ let mut n = idx;
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;
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);
40− hash = (hash ^ (hash >> 30)).wrapping_mul(0xbf58_476d_1ce4_e5b9);
41− hash = (hash ^ (hash >> 27)).wrapping_mul(0x94d0_49bb_1331_11eb);
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";
51− let digit = DIGITS[(n % 36) as usize] as char;
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)]
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)]
74− selector: Vec<String>,
78− /// The condition of an attribute's key, and the name after its
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()),
89− condition.at.sort_unstable();
90− condition.at.dedup();
94− /// Only the at-rule part: a direction under `hover:` is the one without
96− fn at_only(at: &[usize]) -> Condition {
99− selector: Vec::new(),
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)
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> {
113− .position(|p| crate::vocab::element_prefix(p).is_some())
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| {
124− .any(|&b| crate::vocab::at_rule_implied(a, b))
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))
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>);
142−fn at_order(at: &[usize]) -> AtOrder {
145− at.last().copied().unwrap_or(0),
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
159−type SelectorOrder = (bool, Vec<(usize, String)>, Vec<(usize, String)>);
161−fn selector_order(selector: &[String]) -> SelectorOrder {
162− let table = crate::vocab::PSEUDOS;
163− let ranked = |chain: &[String]| -> Vec<(usize, String)> {
167− let name = crate::vocab::pseudo_name(p);
170− .position(|(q, _)| *q == name)
171− .unwrap_or(table.len());
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])),
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) {
190− .position(|p| crate::vocab::element_prefix(p).is_some())
191− .unwrap_or(chain.len());
193− selector_order(&chain[..at]),
194− chain.get(at).cloned().unwrap_or_default(),
195− selector_order(chain.get(at + 1..).unwrap_or_default()),
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);
26+ let mut len = 1;
207− for (i, prefix) in chain.iter().enumerate() {
27+ let mut count = 26usize;
208− if prefix == crate::vocab::CHILDREN {
28+ while n >= count {
209− if Some(i) == last_children {
29+ n -= count;
210− out = format!(":where({})>*", out);
30+ len += 1;
211− } else {
31+ count = count.saturating_mul(36);
214− } else if let Some(pseudo) = crate::vocab::pseudo_selector(prefix) {
215− out.push_str(&pseudo);
218− out
33+ let mut tail = Vec::with_capacity(len - 1);
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..] {
34+ for _ in 1..len {
234− if let Some(pseudo) = crate::vocab::pseudo_selector(prefix) {
35+ tail.push(REST[n % 36]);
235− target.push_str(&pseudo);
36+ n /= 36;
238− Some((root, target))
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()
246− .unwrap_or_default();
247− let name = prefix.trim_end_matches(':');
248− let width = |name: &str| {
251− .find(|(n, _)| *n == name)
252− .map_or("0", |(_, w)| *w)
254− let (kind, feature, value) = if let Some(size) = name.strip_prefix("cq-") {
255− ("@container", "min-width", width(size))
259− return "@media print".to_string();
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)),
269− format!("{} ({}: {})", kind, feature, value)
271− format!("{}({}:{})", kind, feature, value)
273−}
38+ let mut name = String::with_capacity(len);
274−
39+ name.push((b'a' + n as u8) as char);
275−/// A style as text, for its hash: the defaults of its element's kind, its
40+ name.extend(tail.iter().rev().map(|&b| b as char));
276−/// rules (the at-rules' ranks, the selector prefixes and the declarations
41+ name
277−/// of each) and the rules keyed on it, each part ended by a character CSS
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}"));
286− for prefix in &condition.selector {
287− text.push_str(prefix);
291− text.push_str(body);
294− text.push_str(distinct);
298struct StyleEntry {
44struct StyleEntry {
299 class_name: String,
45 class_name: String,
300− /// The hash of the style, which names the class
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,
46+ base: String,
308− /// The element's rules: under each condition, its declarations, in the
47+ /// (CSS selector suffix, css_rules) — e.g. (":hover", "color:red;")
309− /// order they are written
48+ pseudo: Vec<(String, String)>,
310− rules: Vec<(Condition, String)>,
49+ /// Responsive overrides: (breakpoint_prefix, css)
311− /// What else tells two elements with the same CSS apart: the rules
50+ responsive: Vec<(String, String)>,
312− /// keyed on this class (see [`StyleCollector::keyed`]). Not written.
51+ /// Dark mode overrides
313− distinct: String,
54+ print: String,
56+ motion_reduce: String,
59+ /// Container query overrides: (breakpoint_prefix, css)
60+ container: Vec<(String, String)>,
316struct StyleCollector {
63struct StyleCollector {
317 entries: Vec<StyleEntry>,
64 entries: Vec<StyleEntry>,
318− /// Maps a style's hash to its entries (more than one only when two
65+ /// Maps a pre-hashed style signature to an index into `entries`.
319− /// styles hash alike, which the full comparison tells apart).
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.
320 index: HashMap<u64, Vec<usize>>,
68 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)>,
331impl StyleCollector {
71impl StyleCollector {
@@ -333,282 +73,313 @@ impl StyleCollector {
333 StyleCollector {
73 StyleCollector {
334 entries: Vec::new(),
74 entries: Vec::new(),
335 index: HashMap::new(),
75 index: HashMap::new(),
336− names: std::collections::HashSet::new(),
338− keyed_seen: std::collections::HashSet::new(),
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);
350 /// Returns a class name for this style combination, or None if all empty.
79 /// Returns a class name for this style combination, or None if all empty.
80+ #[allow(clippy::too_many_arguments)]
351 fn get_class(
81 fn get_class(
352 &mut self,
82 &mut self,
353− defaults: String,
83+ base: String,
354− mut rules: Vec<(Condition, String)>,
84+ pseudo: Vec<(String, String)>,
355− distinct: String,
85+ responsive: Vec<(String, String)>,
89+ motion_reduce: String,
92+ container: Vec<(String, String)>,
356 ) -> Option<String> {
93 ) -> Option<String> {
357− rules.retain(|(_, body)| !body.is_empty());
94+ if base.is_empty()
358− if defaults.is_empty() && rules.is_empty() {
95+ && pseudo.is_empty()
96+ && responsive.is_empty()
99+ && motion_safe.is_empty()
100+ && motion_reduce.is_empty()
101+ && landscape.is_empty()
102+ && portrait.is_empty()
103+ && container.is_empty()
359 return None;
105 return None;
361− rules.sort_by_cached_key(|(condition, _)| condition.order());
107+ use std::collections::hash_map::DefaultHasher;
362− let style = stable_hash(&style_text(&defaults, &rules, &distinct));
108+ let mut h = DefaultHasher::new();
363−
109+ base.hash(&mut h);
110+ pseudo.hash(&mut h);
111+ responsive.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();
364− if let Some(indices) = self.index.get(&style) {
121+ if let Some(indices) = self.index.get(&sig) {
365 for &idx in indices {
122 for &idx in indices {
366 let e = &self.entries[idx];
123 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
129+ && e.motion_safe == motion_safe
130+ && e.motion_reduce == motion_reduce
131+ && e.landscape == landscape
132+ && e.portrait == portrait
133+ && e.container == container
368 return Some(e.class_name.clone());
135 return Some(e.class_name.clone());
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
375 let idx = self.entries.len();
139 let idx = self.entries.len();
376− let name = (CLASS_DIGITS..=13)
140+ let name = short_class_name(idx);
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());
381 self.entries.push(StyleEntry {
141 self.entries.push(StyleEntry {
382 class_name: name.clone(),
142 class_name: name.clone(),
384− defaults,
144+ pseudo,
385− rules,
145+ responsive,
388− self.index.entry(style).or_default().push(idx);
154+ self.index.entry(sig).or_default().push(idx);
389 Some(name)
155 Some(name)
392− /// The classes given, in the order they were
158+ /// All generated rules, wrapped in `@layer htmlang`.
393− fn classes(&self) -> impl Iterator<Item = Class> + '_ {
394− self.entries.iter().map(|e| Class {
395− name: e.class_name.clone(),
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 {
159+ fn to_css_formatted(&self, dev: bool) -> String {
411− // The defaults: `:where(.hl-a,.hl-b){...}`
412− let mut kind = String::new();
160+ let mut css = String::new();
413− let mut defaults: Vec<(&str, Vec<&str>)> = Vec::new();
161+ let inner_indent = if dev { " " } else { "" };
414− for e in self.entries.iter().filter(|e| !e.defaults.is_empty()) {
162+ css.push_str(if dev { "@layer htmlang {\n" } else { "@layer htmlang{" });
415− match defaults.iter_mut().find(|(body, _)| *body == e.defaults) {
163+
416− Some((_, classes)) => classes.push(&e.class_name),
164+ // Non-responsive rules. Base and pseudo rules are merged separately by
417− None => defaults.push((&e.defaults, vec![&e.class_name])),
165+ // identical body so that e.g. `.a,.b{display:flex;flex-direction:column;}`
418− }
166+ // replaces two identical rules. Pseudo variants are grouped per selector
419− }
167+ // suffix (`:hover` with `:hover`, etc.) to keep each pseudo's cascade
420− for (body, classes) in defaults {
168+ // position independent of others.
421− let classes: Vec<String> = classes.iter().map(|c| format!(".{}", c)).collect();
169+ let mut base_pairs: Vec<(&str, &str)> = Vec::with_capacity(self.entries.len());
422− let selector = format!(":where({})", classes.join(","));
170+ for e in &self.entries {
423− if dev {
171+ if !e.base.is_empty() {
424− kind.push_str(&format!(" {} {{{}}}\n", selector, body));
172+ base_pairs.push((e.class_name.as_str(), e.base.as_str()));
426− kind.push_str(&format!("{}{{{}}}", selector, body));
429−
175+ emit_grouped_rules(&mut css, &base_pairs, "", inner_indent, dev);
430− let mut inside = self.blocks(true, dev);
176+
431− // A function's scoped `@style`, nested under its class
177+ // Collect pseudo rules grouped by selector suffix, preserving the order
432− for block in scoped {
178+ // in which suffixes first appear across entries.
433− if dev {
179+ let mut pseudo_order: Vec<&str> = Vec::new();
434− inside.push_str(block);
180+ let mut pseudo_buckets: HashMap<&str, Vec<(&str, &str)>> = HashMap::new();
435− inside.push('\n');
181+ for e in &self.entries {
436− } else {
182+ for (selector, body) in &e.pseudo {
437− inside.push_str(&compact_css(block));
183+ if body.is_empty() {
186+ let key = selector.as_str();
187+ if !pseudo_buckets.contains_key(key) {
188+ pseudo_order.push(key);
193+ .push((e.class_name.as_str(), body.as_str()));
440−
196+ for selector in &pseudo_order {
441− let mut css = String::new();
197+ if let Some(pairs) = pseudo_buckets.get(selector) {
442− for (name, rules) in [
198+ emit_grouped_rules(&mut css, pairs, selector, inner_indent, dev);
444− ("hl-inside", inside),
445− ("htmlang", self.blocks(false, dev)),
447− if rules.is_empty() {
451− css.push_str(&format!("@layer {} {{\n{}}}\n", name, rules));
453− css.push_str(&format!("@layer {}{{{}}}", name, rules));
459− /// The rules of every block of at-rules, in order: those for the
202+ // Responsive rules grouped by breakpoint
460− /// elements inside (`inside`: rules under an element prefix, each in
203+ for &(bp_name, bp_width) in BREAKPOINTS {
461− /// an `@scope` on its element's class), or the elements' own.
204+ let mut bp_pairs: Vec<(&str, &str)> = Vec::new();
462− fn blocks(&self, inside: bool, dev: bool) -> String {
463− let mut css = String::new();
465− self.entries.iter().flat_map(move |e| {
205+ for e in &self.entries {
466− e.rules
206+ for (bp, rule_css) in &e.responsive {
467− .iter()
207+ if bp == bp_name && !rule_css.is_empty() {
468− .filter(move |(c, _)| c.inside().is_some() == inside)
208+ bp_pairs.push((e.class_name.as_str(), rule_css.as_str()));
469− .map(move |(c, body)| (e, c, body))
472− let mut blocks: Vec<&[usize]> = vec![&[]];
473− let keyed = self.keyed.iter().filter(|_| !inside);
475− .map(|(_, c, _)| c.at.as_slice())
476− .chain(keyed.map(|(at, _, _)| at.as_slice()));
478− if !blocks.contains(&at) {
482− blocks.sort_by_key(|at| at_order(at));
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))
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
498− let keyed: Vec<(&str, &str)> = self
501− .filter(|(a, _, _)| a.as_slice() == at)
502− .map(|(_, selector, body)| (selector.as_str(), body.as_str()))
504− emit_selector_rules(&mut inner, &keyed, &indent, dev);
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);
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
519− let mut scopes: Vec<(String, Vec<(String, &str)>)> = Vec::new();
520− for chain in chains {
521− let Some(element) = chain
523− .position(|p| crate::vocab::element_prefix(p).is_some())
528− rules().filter(|(_, c, _)| c.at == at && c.selector == chain)
530− let Some((root, target)) = scoped_selector(&e.class_name, chain, element)
534− match scopes.iter_mut().find(|(r, _)| *r == root) {
535− Some((_, targets)) => targets.push((target, body)),
536− None => scopes.push((root, vec![(target, body)])),
540− let inner_indent = if dev {
541− format!("{} ", indent)
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 { "}" });
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()))
562− emit_grouped_rules(&mut inner, &pairs, &indent, dev);
565− if inner.is_empty() {
568− // Each at-rule wraps the next, outermost first
212+ emit_media_block(
569− for (level, &rank) in at.iter().enumerate().rev() {
213+ &mut css,
570− let pad = if dev {
214+ &format!("@media (min-width: {})", bp_width),
571− " ".repeat(level)
215+ &format!("@media(min-width:{})", bp_width),
572− } else {
216+ &bp_pairs,
573− String::new()
217+ "",
575− inner = if dev {
219+ );
576− format!("{pad}{} {{\n{inner}{pad}}}\n", at_rule(rank, true))
220+ }
578− format!("{}{{{inner}}}", at_rule(rank, false))
222+ // Dark mode rules
223+ let dark_pairs: Vec<(&str, &str)> = self
226+ .filter(|e| !e.dark.is_empty())
227+ .map(|e| (e.class_name.as_str(), e.dark.as_str()))
231+ "@media (prefers-color-scheme: dark)",
232+ "@media(prefers-color-scheme:dark)",
239+ let print_pairs: Vec<(&str, &str)> = self
242+ .filter(|e| !e.print.is_empty())
243+ .map(|e| (e.class_name.as_str(), e.print.as_str()))
254+ // Motion safe rules
255+ let motion_safe_pairs: Vec<(&str, &str)> = self
258+ .filter(|e| !e.motion_safe.is_empty())
259+ .map(|e| (e.class_name.as_str(), e.motion_safe.as_str()))
263+ "@media (prefers-reduced-motion: no-preference)",
264+ "@media(prefers-reduced-motion:no-preference)",
270+ // Motion reduce rules
271+ let motion_reduce_pairs: Vec<(&str, &str)> = self
274+ .filter(|e| !e.motion_reduce.is_empty())
275+ .map(|e| (e.class_name.as_str(), e.motion_reduce.as_str()))
279+ "@media (prefers-reduced-motion: reduce)",
280+ "@media(prefers-reduced-motion:reduce)",
281+ &motion_reduce_pairs,
287+ let landscape_pairs: Vec<(&str, &str)> = self
290+ .filter(|e| !e.landscape.is_empty())
291+ .map(|e| (e.class_name.as_str(), e.landscape.as_str()))
295+ "@media (orientation: landscape)",
296+ "@media(orientation:landscape)",
303+ let portrait_pairs: Vec<(&str, &str)> = self
306+ .filter(|e| !e.portrait.is_empty())
307+ .map(|e| (e.class_name.as_str(), e.portrait.as_str()))
311+ "@media (orientation: portrait)",
312+ "@media(orientation:portrait)",
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()));
581− css.push_str(&inner);
328+ emit_media_block(
330+ &format!("@container (min-width: {})", bp_width),
331+ &format!("@container(min-width:{})", bp_width),
338+ css.push_str(if dev { "}\n" } else { "}" });
587−/// Emit CSS rules from `(selector, body)` pairs, merging identical bodies
343+/// Emit CSS rules from `(class_name, body)` pairs, merging identical bodies
588/// into a single selector-list rule (e.g. `.a,.b{body}`). The first occurrence
344/// into a single selector-list rule (e.g. `.a,.b{body}`). The first occurrence
589/// of each distinct body determines ordering, so output stays deterministic
345/// of each distinct body determines ordering, so output stays deterministic
346+/// across runs. `selector_suffix` is appended to each class (e.g. `":hover"`,
590−/// across runs. `indent` is prepended to each rule line.
347+/// or `""` for plain class rules). `indent` is prepended to each rule line.
591−fn emit_grouped_rules(out: &mut String, pairs: &[(String, &str)], indent: &str, dev: bool) {
348+fn emit_grouped_rules(
350+ pairs: &[(&str, &str)],
351+ selector_suffix: &str,
592 if pairs.is_empty() {
355 if pairs.is_empty() {
595 // Group in first-occurrence order.
358 // Group in first-occurrence order.
596 let mut order: Vec<&str> = Vec::new();
359 let mut order: Vec<&str> = Vec::new();
597 let mut groups: HashMap<&str, Vec<&str>> = HashMap::new();
360 let mut groups: HashMap<&str, Vec<&str>> = HashMap::new();
598− for (selector, body) in pairs {
361+ for &(name, body) in pairs {
599 if body.is_empty() {
362 if body.is_empty() {
600 continue;
363 continue;
602 if !groups.contains_key(body) {
365 if !groups.contains_key(body) {
603 order.push(body);
366 order.push(body);
605− groups.entry(body).or_default().push(selector);
368+ groups.entry(body).or_default().push(name);
607 let sp = if dev { " " } else { "" };
370 let sp = if dev { " " } else { "" };
608 let nl = if dev { "\n" } else { "" };
371 let nl = if dev { "\n" } else { "" };
609 for body in &order {
372 for body in &order {
373+ let names = &groups[body];
610 out.push_str(indent);
374 out.push_str(indent);
611− out.push_str(&groups[body].join(","));
375+ for (i, n) in names.iter().enumerate() {
381+ out.push_str(selector_suffix);
612 out.push_str(sp);
383 out.push_str(sp);
613 out.push('{');
384 out.push('{');
614 out.push_str(body);
385 out.push_str(body);
@@ -617,44 +388,38 @@ fn emit_grouped_rules(out: &mut String, pairs: &[(String, &str)], indent: &str,
620−/// Emit `(selector, body)` rules in their order, merging a run of rules
391+/// Emit an `@media` / `@container` block containing grouped class rules.
621−/// with the same body into one rule with a selector list (the order
392+/// Skips the block entirely if no non-empty bodies are present.
622−/// matters: two rules may apply to one element).
393+fn emit_media_block(
623−fn emit_selector_rules(out: &mut String, rules: &[(&str, &str)], indent: &str, dev: bool) {
394+ out: &mut String,
624− let mut i = 0;
395+ header_dev: &str,
625− while i < rules.len() {
396+ header_min: &str,
626− let body = rules[i].1;
397+ pairs: &[(&str, &str)],
627− let run = rules[i..].iter().take_while(|(_, b)| *b == body).count();
398+ selector_suffix: &str,
628− if !body.is_empty() {
399+ dev: bool,
629− let selectors: Vec<&str> = rules[i..i + run].iter().map(|(s, _)| *s).collect();
400+) {
630− out.push_str(indent);
401+ if pairs.iter().all(|(_, body)| body.is_empty()) {
631− out.push_str(&selectors.join(","));
402+ return;
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() {
632− if dev {
410+ if dev {
633− out.push(' ');
411+ out.push_str(&format!("{} {{\n{}}}\n", header_dev, inner));
636− out.push_str(body);
413+ out.push_str(&format!("{}{{{}}}", header_min, inner));
646struct GenContext {
417struct GenContext {
647 dev: bool,
418 dev: bool,
648 depth: usize,
419 depth: usize,
649 has_interactive: bool,
421 has_interactive: bool,
650− /// Writing inside a text element, at any depth: htmlang's own `<div>`s
422+ has_defer: bool,
651− /// are `<span>`s there, which text can hold.
653− /// How the element whose children are being written lays them out
655− /// Writing the children of a `@picture`, where `@source`'s leading
656− /// argument is its `srcset`
660impl GenContext {
425impl GenContext {
@@ -680,26 +445,23 @@ pub struct CodegenOptions {
680 pub dev: bool,
445 pub dev: bool,
681 pub partial: bool,
446 pub partial: bool,
682 pub minify: bool,
447 pub minify: bool,
685/// Generate HTML from a parsed document using the given options.
451/// Generate HTML from a parsed document using the given options.
686pub fn generate_with(doc: &Document, opts: &CodegenOptions) -> String {
452pub fn generate_with(doc: &Document, opts: &CodegenOptions) -> String {
687− generate_with_classes(doc, opts).0
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();
694 let mut html = if opts.partial {
453 let mut html = if opts.partial {
695− generate_partial_inner(doc, opts.dev, &mut classes)
454+ generate_partial_inner(doc, opts.dev)
697− generate_full_inner(doc, opts.dev, &mut classes)
456+ generate_full_inner(doc, opts.dev)
699 if opts.minify {
458 if opts.minify {
700 html = minify_html(&html);
459 html = minify_html(&html);
702− (html, classes)
461+ if opts.compat {
462+ html = add_vendor_prefixes(&html);
705pub fn generate(doc: &Document) -> String {
467pub fn generate(doc: &Document) -> String {
@@ -747,6 +509,38 @@ pub fn generate_minified(doc: &Document) -> String {
512+pub fn generate_compat(doc: &Document) -> String {
517+ ..Default::default()
522+pub fn generate_dev_compat(doc: &Document) -> String {
528+ ..Default::default()
533+pub fn generate_minified_compat(doc: &Document) -> String {
539+ ..Default::default()
750fn minify_html(html: &str) -> String {
544fn minify_html(html: &str) -> String {
751 let mut result = String::with_capacity(html.len());
545 let mut result = String::with_capacity(html.len());
752 let mut in_pre = false;
546 let mut in_pre = false;
@@ -825,149 +619,578 @@ fn minify_html(html: &str) -> String {
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..];
640+ result.push_str(rest);
644+fn prefix_css(css: &str) -> String {
645+ let mut out = String::with_capacity(css.len() + 256);
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]);
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));
662+ out.push_str(&css[i..]);
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() {
676+ if let Some((prop, val)) = decl.split_once(':') {
677+ let prop = prop.trim();
678+ let val = val.trim();
680+ "backdrop-filter" => {
681+ out.push_str(&format!("-webkit-backdrop-filter:{};", val));
682+ out.push_str(&format!("backdrop-filter:{};", val));
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));
690+ out.push_str(&format!("-webkit-appearance:{};", val));
691+ out.push_str(&format!("-moz-appearance:{};", val));
692+ out.push_str(&format!("appearance:{};", val));
694+ "background-clip" if val.contains("text") => {
695+ out.push_str(&format!("-webkit-background-clip:{};", val));
696+ out.push_str(&format!("background-clip:{};", val));
699+ out.push_str(&format!("-webkit-hyphens:{};", val));
700+ out.push_str(&format!("-ms-hyphens:{};", val));
701+ out.push_str(&format!("hyphens:{};", val));
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));
708+ "mask-image" | "mask-size" | "mask-repeat" | "mask-position" => {
709+ out.push_str(&format!("-webkit-{}:{};", prop, val));
710+ out.push_str(&format!("{}:{};", prop, val));
828−fn generate_full_inner(doc: &Document, dev: bool, classes: &mut Vec<Class>) -> String {
725+fn generate_full_inner(doc: &Document, dev: bool) -> String {
829− // Without `@page` the output is a fragment
830− let Some(page) = &doc.page else {
831− return generate_partial_inner(doc, dev, classes);
833 let mut styles = StyleCollector::new();
726 let mut styles = StyleCollector::new();
834 let mut ctx = GenContext {
727 let mut ctx = GenContext {
836 depth: 0,
729 depth: 0,
837 has_interactive: false,
731 has_interactive: false,
838− in_text: false,
732+ has_defer: false,
839− flow: Flow::default(),
843− // The page is the root element: `<body>` is a column (the reset makes
735+ // Check if document has @main for skip-to-content link
844− // it one, filling the viewport), `@page`'s styles are its class, and
736+ let has_main = has_element_kind(&doc.nodes, &ElementKind::Main);
845− // the page's top-level elements are its children
846− let root = Element {
847− kind: ElementKind::El,
848− attrs: page.styles.clone(),
850− children: Vec::new(),
854− let mut own = Flow::of(&root);
855− let top = Flow::default();
859− has_overlay_children: holds_overlays(&doc.nodes),
863− let body_class = element_class(&root, &site, &mut styles);
864− own.class = body_class.clone();
867 let mut body = String::new();
738 let mut body = String::new();
870− Some(Layout::Column),
876− let element_css = build_element_css(doc, &styles, dev);
877− let nl = if dev { "\n" } else { "" };
879− let mut meta_html = String::new();
740+ // Skip-to-content link for accessibility (only when @main exists)
880− // A `@meta viewport` of the page's own replaces the usual one
741+ if has_main {
881− if !doc.meta_tags.iter().any(|(name, _)| name == "viewport") {
742+ if dev {
882− meta_html.push_str(&format!(
743+ body.push_str("<a href=\"#hl-main\" class=\"hl-skip\">Skip to content</a>\n");
883− "<meta name=\"viewport\" content=\"width=device-width, initial-scale=1\">{}",
744+ } else {
884− nl
745+ body.push_str("<a href=\"#hl-main\" class=\"hl-skip\">Skip to content</a>");
887− meta_html.push_str(&format!(
888− "<title>{}</title>{}",
889− html_escape(&page.title),
892− for (name, content) in &doc.meta_tags {
893− meta_html.push_str(&format!(
894− "<meta name=\"{}\" content=\"{}\">{}",
896− html_escape(content),
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),
908− if let Some(path) = &page.favicon {
909− meta_html.push_str(&format!(
910− "<link rel=\"icon\" href=\"{}\">{}",
915− for block in &doc.head_blocks {
916− meta_html.push_str(block);
917− meta_html.push_str(nl);
920− // `@page`'s HTML attributes go on `<html>`
749+ for node in &doc.nodes {
921− let mut root_attrs = String::new();
750+ generate_node(node, None, &mut body, &mut styles, &mut ctx);
922− for attr in html_attrs(&page.html_attrs) {
923− push_html_attr(&mut root_attrs, attr);
925− let mut body_attrs = String::new();
926− emit_class_attr(&mut body_attrs, body_class.as_deref(), None);
928− // Focus-visible CSS for interactive elements (accessibility)
753+ // Collect external domains for DNS prefetch
929− let focus_visible_css = if ctx.has_interactive {
754+ let dns_prefetch_html = collect_dns_prefetch(&body, dev);
930− let focusable = ":where(a,button,input,select,textarea):focus-visible";
755+
931− if dev {
756+ let element_css = build_element_css(doc, &styles, dev);
933− "{}{} {{ outline: 2px solid currentColor; outline-offset: 2px; }}\n",
758+ // Build meta tags string
934− OWN_ELEMENTS, focusable
759+ let meta_html = if doc.meta_tags.is_empty() {
938− "{}{}{{outline:2px solid currentColor;outline-offset:2px}}",
939− OWN_ELEMENTS, focusable
943 String::new()
760 String::new()
762+ let mut m = String::new();
763+ for (name, content) in &doc.meta_tags {
765+ m.push_str(&format!(
766+ "<meta name=\"{}\" content=\"{}\">\n",
768+ html_escape(content)
771+ m.push_str(&format!(
772+ "<meta name=\"{}\" content=\"{}\">",
774+ html_escape(content)
945− let reset_css = reset_css(dev, true, &focus_visible_css);
946− classes.extend(styles.classes());
948− format!(
781+ // Build OG meta tags
949− "<!DOCTYPE html>{nl}<html{root_attrs}>{nl}<head>{nl}<meta charset=\"utf-8\">{nl}\
782+ let og_html = if doc.og_tags.is_empty() {
950− {meta_html}<style>{nl}{reset_css}{element_css}</style>{nl}</head>{nl}\
783+ String::new()
951− <body{body_attrs}>{nl}{body}</body>{nl}</html>{nl}",
784+ } else {
785+ let mut o = String::new();
786+ for (property, content) in &doc.og_tags {
788+ o.push_str(&format!(
789+ "<meta property=\"og:{}\" content=\"{}\">\n",
790+ html_escape(property),
791+ html_escape(content)
794+ o.push_str(&format!(
795+ "<meta property=\"og:{}\" content=\"{}\">",
796+ html_escape(property),
797+ html_escape(content)
955−/// Assemble every CSS block the document needs (font faces, custom
804+ // Build head blocks string
956−/// properties, generated class rules, keyframes, and user CSS). Shared by
805+ let head_html = if doc.head_blocks.is_empty() {
957−/// full-page and partial output so both emit the same styles.
806+ String::new()
958−fn build_element_css(doc: &Document, styles: &StyleCollector, dev: bool) -> String {
807+ } else {
959− let mut element_css = String::new();
808+ let mut h = String::new();
809+ for block in &doc.head_blocks {
961− // Collect the CSS custom properties declared with `@let --name` so they
818+ let lang_attr = match &doc.lang {
962− // can be emitted in a single `:root` block below.
819+ Some(lang) => format!(" lang=\"{}\"", html_escape(lang)),
963− let mut root_vars: Vec<(String, String)> = Vec::new();
820+ None => String::new(),
964− for (name, value) in &doc.css_vars {
965− root_vars.push((name.clone(), value.clone()));
823+ let favicon_html = match &doc.favicon {
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") {
829+ } else if path.ends_with(".png") {
831+ } else if path.ends_with(".svg") {
836+ let b64 = base64_encode(&data);
839+ "<link rel=\"icon\" href=\"data:{};base64,{}\">\n",
843+ format!("<link rel=\"icon\" href=\"data:{};base64,{}\">", mime, b64)
846+ // Fall back to href
848+ format!("<link rel=\"icon\" href=\"{}\">\n", html_escape(path))
850+ format!("<link rel=\"icon\" href=\"{}\">", html_escape(path))
854+ None => String::new(),
858+ let canonical_html = match &doc.canonical {
861+ format!("<link rel=\"canonical\" href=\"{}\">\n", html_escape(url))
863+ format!("<link rel=\"canonical\" href=\"{}\">", html_escape(url))
866+ None => String::new(),
870+ let base_html = match &doc.base_url {
873+ format!("<base href=\"{}\">\n", html_escape(url))
875+ format!("<base href=\"{}\">", html_escape(url))
878+ None => String::new(),
882+ let json_ld_html: String = doc
888+ "<script type=\"application/ld+json\">\n{}\n</script>\n",
892+ format!("<script type=\"application/ld+json\">{}</script>", block)
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)));
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)));
909+ if let Some(ref tc) = manifest.theme_color {
910+ json.push_str(&format!(",\"theme_color\":{}", json_str(tc)));
912+ if let Some(ref desc) = manifest.description {
913+ json.push_str(&format!(",\"description\":{}", json_str(desc)));
915+ if !manifest.icons.is_empty() {
916+ json.push_str(",\"icons\":[");
917+ for (i, (src, sizes)) in manifest.icons.iter().enumerate() {
921+ json.push_str(&format!(
922+ "{{\"src\":{},\"sizes\":{},\"type\":\"image/png\"}}",
931+ // Inline the manifest as a data URI
932+ let encoded = base64_encode(json.as_bytes());
935+ "<link rel=\"manifest\" href=\"data:application/manifest+json;base64,{}\">\n",
940+ "<link rel=\"manifest\" href=\"data:application/manifest+json;base64,{}\">",
948+ // Preload hints (auto-detect fonts from @font-face)
949+ let mut preload_html = String::new();
950+ for (_, url) in &doc.font_faces {
952+ preload_html.push_str(&format!(
953+ "<link rel=\"preload\" href=\"{}\" as=\"font\" type=\"font/woff2\" crossorigin>\n",
957+ preload_html.push_str(&format!(
958+ "<link rel=\"preload\" href=\"{}\" as=\"font\" type=\"font/woff2\" crossorigin>",
963+ // Explicit preload hints from the document
964+ for hint in &doc.preload_hints {
966+ preload_html.push_str(&format!(
967+ "<link rel=\"preload\" href=\"{}\" as=\"{}\"{}>\n",
968+ html_escape(&hint.href),
970+ if hint.crossorigin { " crossorigin" } else { "" }
973+ preload_html.push_str(&format!(
974+ "<link rel=\"preload\" href=\"{}\" as=\"{}\"{}>",
975+ html_escape(&hint.href),
977+ if hint.crossorigin { " crossorigin" } else { "" }
982+ // Auto theme-color meta from @theme primary token
983+ let theme_color_html = doc
986+ .find(|(name, _)| name == "primary" || name == "theme-color")
990+ "<meta name=\"theme-color\" content=\"{}\">\n",
995+ "<meta name=\"theme-color\" content=\"{}\">",
1000+ .unwrap_or_default();
1002+ // Focus-visible CSS for interactive elements (accessibility)
1003+ let focus_visible_css = if ctx.has_interactive {
1005+ "a:focus-visible, button:focus-visible, input:focus-visible, select:focus-visible, textarea:focus-visible { outline: 2px solid currentColor; outline-offset: 2px; }\n"
1007+ "a:focus-visible,button:focus-visible,input:focus-visible,select:focus-visible,textarea:focus-visible{outline:2px solid currentColor;outline-offset:2px}"
1013+ // Skip-to-content CSS (visually hidden but accessible)
1014+ let skip_link_css = if has_main {
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"
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}"
1024+ // Noscript fallback: show deferred content if JS is disabled
1025+ let noscript_html = if ctx.has_defer {
1027+ "<noscript><style>.hl-defer-placeholder { display: none; }</style></noscript>\n"
1029+ "<noscript><style>.hl-defer-placeholder{display:none}</style></noscript>"
1035+ let reset_css = reset_css(dev, focus_visible_css, skip_link_css);
1037+ match &doc.page_title {
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}\
1050+{reset_css}{element_css}\
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,
1072+ reset_css = reset_css,
1073+ noscript_html = noscript_html,
1074+ element_css = element_css,
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,
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,
1101+ if element_css.is_empty() {
1104+ format!("<style>\n{}</style>\n{}", element_css, body)
1106+ format!("<style>{}</style>{}", element_css, body)
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);
1116+ for c in s.chars() {
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)),
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();
1137+ // @font-face rules, in declaration order
1138+ for (name, url) in &doc.font_faces {
1139+ let format_hint = if url.ends_with(".woff2") {
1141+ } else if url.ends_with(".woff") {
1143+ } else if url.ends_with(".ttf") {
1144+ " format('truetype')"
1145+ } else if url.ends_with(".otf") {
1146+ " format('opentype')"
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
1156+ element_css.push_str(&format!(
1157+ "@font-face{{font-family:'{}';src:url('{}'){};font-display:swap}}",
1158+ name, url, format_hint
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()));
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()));
968− // Generated rules always go in htmlang's layers, so unlayered user CSS
1177+ // Generated rules always go in `@layer htmlang`, so unlayered user CSS
969− // (`@style`, `@raw`) overrides them regardless of specificity.
1178+ // (`@style`, `@raw`) overrides them regardless of specificity.
970− let styles_css = styles.to_css_formatted(dev, &doc.scoped_css);
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 {
1190+ let (new_css, auto_vars) = auto_extract_repeats(&styles_css, &root_vars);
1191+ root_vars.extend(auto_vars);
972 // Emit the :root block first so the cascade picks up the custom
1195 // Emit the :root block first so the cascade picks up the custom
973 // properties before the class rules consume them.
1196 // properties before the class rules consume them.
@@ -992,121 +1215,72 @@ fn build_element_css(doc: &Document, styles: &StyleCollector, dev: bool) -> Stri
993 element_css.push_str(&styles_css);
1216 element_css.push_str(&styles_css);
1219+ for (name, kf_body) in &doc.keyframes {
1221+ element_css.push_str(&format!("@keyframes {} {{\n{}\n}}\n", name, kf_body));
1223+ element_css.push_str(&format!("@keyframes {}{{{}}}", name, kf_body));
1227+ // Auto-inject skeleton keyframe if skeleton attribute is used
1228+ if element_css.contains("hl-skeleton") {
1230+ element_css.push_str("@keyframes hl-skeleton {\n 0% { background-position: 200% 0; }\n 100% { background-position: -200% 0; }\n}\n");
1232+ element_css.push_str("@keyframes hl-skeleton{0%{background-position:200% 0}100%{background-position:-200% 0}}");
995 // @style blocks (custom CSS)
1236 // @style blocks (custom CSS)
996 for block in &doc.custom_css {
1237 for block in &doc.custom_css {
997 if dev {
1238 if dev {
998 element_css.push_str(block);
1239 element_css.push_str(block);
999 element_css.push('\n');
1240 element_css.push('\n');
1000 } else {
1241 } else {
1242+ let minified: String = block.lines().map(|l| l.trim()).collect::<Vec<_>>().join("");
1001− element_css.push_str(&compact_css(block));
1243+ element_css.push_str(&minified);
1005 element_css
1247 element_css
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 {
1015− .filter(|l| !l.is_empty())
1016− .collect::<Vec<_>>()
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-\"])";
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"];
1036/// Built-in reset rules, in a layer before `htmlang`: unlayered CSS beats
1250/// Built-in reset rules, in a layer before `htmlang`: unlayered CSS beats
1037−/// every layer, so an unlayered rule here would override the generated
1251+/// every layer, so an unlayered `a{color:inherit}` would override
1038−/// ones. A page resets `box-sizing` everywhere and makes `<body>` a column
1252+/// `@link [color red]`.
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 {
1253+fn reset_css(dev: bool, focus_visible_css: &str, skip_link_css: &str) -> String {
1045− let own = OWN_ELEMENTS;
1254+ let base = if dev {
1046− let mut rules = Vec::new();
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"
1048− rules.push(if dev {
1049− "*, *::before, *::after { box-sizing: border-box; }".to_string()
1051− "*,*::before,*::after{box-sizing:border-box}".to_string()
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()
1056− "body{margin:0;font-family:system-ui,-apple-system,sans-serif;display:flex;flex-direction:column;min-height:100dvh}".to_string()
1059− rules.push(if dev {
1060− format!("{own}, {own}::before, {own}::after {{ box-sizing: border-box; }}")
1062− format!("{own},{own}::before,{own}::after{{box-sizing:border-box}}")
1065− let hidden = "[hidden]:not([hidden=\"until-found\"]),dialog:not([open]):not(:popover-open),\
1066− [popover]:not(:popover-open):not(dialog[open])";
1067− rules.push(if dev {
1068− format!("{own}:where({hidden}) {{ display: none !important; }}")
1069 } else {
1256 } else {
1070− format!("{own}:where({hidden}){{display:none!important}}")
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}"
1072− let mut rules = rules.join(if dev { "\n" } else { "" });
1076− rules.push_str(focus_visible_css);
1259+ let rules = format!("{}{}{}", base, focus_visible_css, skip_link_css);
1077 if dev {
1260 if dev {
1079− "@layer {};\n@layer hl-reset {{\n{}}}\n",
1261+ format!("@layer hl-reset, htmlang;\n@layer hl-reset {{\n{}}}\n", rules)
1083 } else {
1262 } else {
1084− format!("@layer {};@layer hl-reset{{{}}}", LAYERS.join(","), rules)
1263+ format!("@layer hl-reset,htmlang;@layer hl-reset{{{}}}", rules)
1088/// Generate an HTML fragment: body + optional <style>, no <html>/<head>/<body> wrapper.
1267/// 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 {
1090 let mut styles = StyleCollector::new();
1269 let mut styles = StyleCollector::new();
1091 let mut ctx = GenContext {
1270 let mut ctx = GenContext {
1093 depth: 0,
1272 depth: 0,
1094 has_interactive: false,
1274 has_interactive: false,
1095− in_text: false,
1275+ has_defer: false,
1096− flow: Flow::default(),
1099 let mut body = String::new();
1277 let mut body = String::new();
1101− generate_children(&doc.nodes, None, &mut body, &mut styles, &mut ctx);
1279+ for node in &doc.nodes {
1102−
1280+ generate_node(node, None, &mut body, &mut styles, &mut ctx);
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, ""));
1109− classes.extend(styles.classes());
1282+
1283+ let element_css = build_element_css(doc, &styles, dev);
1111 if element_css.is_empty() {
1285 if element_css.is_empty() {
@@ -1121,20 +1295,44 @@ fn generate_partial_inner(doc: &Document, dev: bool, classes: &mut Vec<Class>) -
1121// Node generation
1295// Node generation
1122// ---------------------------------------------------------------------------
1296// ---------------------------------------------------------------------------
1124−/// Write `node`, which is inside an element with the layout `parent`
1125−/// (`None` at the top of the page).
1126fn generate_node(
1298fn generate_node(
1127 node: &Node,
1299 node: &Node,
1128− parent: Option<Layout>,
1300+ parent_kind: Option<&ElementKind>,
1129 out: &mut String,
1301 out: &mut String,
1130 styles: &mut StyleCollector,
1302 styles: &mut StyleCollector,
1131 ctx: &mut GenContext,
1303 ctx: &mut GenContext,
1133 match node {
1305 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),
1135 Node::Text(segments) => {
1307 Node::Text(segments) => {
1136− // In a row, column or grid each line of text is a child
1308+ let needs_wrap = matches!(
1137− let needs_wrap = parent.is_some_and(Layout::is_container);
1309+ parent_kind,
1310+ Some(ElementKind::Row)
1311+ | Some(ElementKind::Column)
1312+ | Some(ElementKind::El)
1313+ | Some(ElementKind::Nav)
1314+ | Some(ElementKind::Header)
1315+ | Some(ElementKind::Footer)
1316+ | Some(ElementKind::Main)
1317+ | Some(ElementKind::Section)
1318+ | Some(ElementKind::Article)
1319+ | Some(ElementKind::Aside)
1320+ | Some(ElementKind::ListItem)
1321+ | Some(ElementKind::Form)
1322+ | Some(ElementKind::Details)
1323+ | Some(ElementKind::Figure)
1324+ | Some(ElementKind::Blockquote)
1325+ | Some(ElementKind::Dialog)
1326+ | Some(ElementKind::DefinitionList)
1327+ | Some(ElementKind::DefinitionDescription)
1328+ | Some(ElementKind::Fieldset)
1329+ | Some(ElementKind::Datalist)
1330+ | Some(ElementKind::Grid)
1331+ | Some(ElementKind::Stack)
1332+ | Some(ElementKind::Noscript)
1333+ | Some(ElementKind::Address)
1334+ | Some(ElementKind::Search)
1138 if needs_wrap {
1336 if needs_wrap {
1139 out.push_str(&ctx.indent());
1337 out.push_str(&ctx.indent());
1140 out.push_str("<span>");
1338 out.push_str("<span>");
@@ -1153,191 +1351,209 @@ fn generate_node(
1156−/// What goes between two things written one after the other in an element
1354+/// HTML attributes that are passed through to the HTML tag rather than converted to CSS.
1157−/// with this layout (`None`: the top of the page): text flows, so its lines
1355+const HTML_PASSTHROUGH_ATTRS: &[&str] = &[
1158−/// and children are joined with a space; in HTML's own layout, and at the
1356+ "type",
1159−/// top of the page, two lines of text are separated by a line break (a
1357+ "placeholder",
1160−/// space, except where whitespace is kept, as in `@pre`).
1358+ "name",
1161−fn separator(layout: Option<Layout>, previous_is_text: bool, next: &Node) -> Option<char> {
1359+ "value",
1162− match layout {
1360+ "disabled",
1163− Some(Layout::Text) => Some(' '),
1361+ "required",
1164− Some(Layout::Native) | None if previous_is_text && matches!(next, Node::Text(_)) => {
1362+ "checked",
1165− Some('\n')
1363+ "for",
1167− _ => None,
1365+ "method",
1168− }
1366+ "autocomplete",
1388+ // Image optimization
1391+ // Media src (explicit attribute form)
1393+ // New element attributes
1414+ "popovertargetaction",
1415+ // Modern form/input hints
1418+ // Performance hints
1424+ // ARIA live regions
1171−/// Write the children of an element (or of a `@fragment`, which has no
1430+/// Boolean HTML attributes (rendered without a value, e.g., `<input disabled>`).
1172−/// element of its own) laid out as `layout` (`None`: the top of the page).
1431+const BOOLEAN_HTML_ATTRS: &[&str] = &[
1173−/// The first line of an element's text is its first child.
1432+ "disabled",
1174−fn generate_children(
1433+ "required",
1175− children: &[Node],
1434+ "checked",
1176− layout: Option<Layout>,
1435+ "multiple",
1177− out: &mut String,
1436+ "controls",
1178− styles: &mut StyleCollector,
1437+ "autoplay",
1179− ctx: &mut GenContext,
1438+ "loop",
1181− generate_run(children, layout, &mut None, out, styles, ctx);
1440+ "playsinline",
1184−/// [`generate_children`], with `previous` saying whether what was written
1451+fn emit_html_passthrough_attrs(out: &mut String, attrs: &[Attribute]) {
1185−/// last was a line of text (`None`: nothing yet). A `@fragment`'s children
1452+ for attr in attrs {
1186−/// are written as if they stood in its place, so its lines are separated
1453+ let key = attr.key.as_str();
1187−/// from the lines around it like any other lines.
1454+ let is_passthrough = HTML_PASSTHROUGH_ATTRS.contains(&key)
1188−fn generate_run(
1455+ || key.starts_with("aria-")
1189− children: &[Node],
1456+ || key.starts_with("data-");
1190− layout: Option<Layout>,
1457+ if !is_passthrough {
1191− previous: &mut Option<bool>,
1193− styles: &mut StyleCollector,
1194− ctx: &mut GenContext,
1196− for child in children {
1197− if let Node::Element(elem) = child
1198− && elem.kind == ElementKind::Fragment
1200− generate_run(&elem.children, layout, previous, out, styles, ctx);
1201 continue;
1458 continue;
1203− let start = out.len();
1460+ if BOOLEAN_HTML_ATTRS.contains(&key) && attr.value.is_none() {
1204− if let Some(previous_is_text) = *previous
1461+ out.push(' ');
1205− && let Some(sep) = separator(layout, previous_is_text, child)
1462+ out.push_str(key);
1206− {
1463+ } else if let Some(val) = &attr.value {
1207− out.push(sep);
1464+ out.push(' ');
1208− }
1465+ out.push_str(key);
1209− let body = out.len();
1466+ out.push_str("=\"");
1210− generate_node(child, layout, out, styles, ctx);
1467+ out.push_str(&html_escape(strip_string_quotes(val)));
1211− // A child that writes nothing (an empty `@fragment`) takes no
1468+ out.push('"');
1212− // separator either, so text never gets two spaces in a row
1213− if out.len() == body {
1214− out.truncate(start);
1217− *previous = Some(matches!(child, Node::Text(_)));
1221−/// Emit the element's leading argument as its attribute (`@iframe URL` →
1473+/// If the value is wrapped in a single pair of matching quotes (e.g.
1222−/// `src="URL"`, `@form /submit` → `action="/submit"`, `@link /a` →
1474+/// `"Avatar"`), return the inner content. Quotes act as source-level
1223−/// `href="/a"`), first, before the class. `@image [inline] photo.png` puts
1475+/// delimiters in the `.hl` syntax and shouldn't leak into HTML attribute
1224−/// the file itself into the page.
1476+/// values. Multi-quoted values like `"h h" "s m"` are left unchanged —
1225−fn emit_argument_attr(out: &mut String, elem: &Element, in_picture: bool) {
1477+/// those are real string tokens (used e.g. by CSS `grid-template-areas`).
1226− let (Some(attr), Some(value)) = (elem.kind.leading_attribute(in_picture), &elem.argument)
1478+fn strip_string_quotes(val: &str) -> &str {
1227− else {
1479+ let bytes = val.as_bytes();
1228− return;
1480+ if bytes.len() < 2 {
1229− };
1481+ return val;
1230− // `@image [inline]`'s file is already a `data:` URI (see the parser)
1231− let value = html_escape(value);
1233− out.push_str(attr);
1234− out.push_str("=\"");
1235− out.push_str(&value);
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
1244− .map(str::to_ascii_lowercase)
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",
1256− format!("data:{};base64,{}", mime, base64_encode(data))
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);
1268−}
1483+ let first = bytes[0];
1269−
1484+ let last = bytes[bytes.len() - 1];
1270−/// The HTML attributes of `attrs`, `key=value` ones and flags, each name
1485+ if (first == b'"' && last == b'"') || (first == b'\'' && last == b'\'') {
1271−/// once: the later one wins, as a style does. (Of two attributes with one
1486+ let inner = &val[1..val.len() - 1];
1272−/// name, the browser keeps the first, so a bundle's attribute or a
1487+ if !inner.as_bytes().contains(&first) {
1273−/// function's own would win over one written after it.)
1488+ return inner;
1274−fn html_attrs(attrs: &[Attribute]) -> impl Iterator<Item = &Attribute> {
1489+ }
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..]
1280− .any(|other| is_html(other) && other.key == attr.key);
1281− (is_html(attr) && !later).then_some(attr)
1285−/// ` key="value"`, or ` key` for a flag.
1286−fn push_html_attr(out: &mut String, attr: &Attribute) {
1288− out.push_str(&attr.key);
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("")));
1297// True if any direct child is `@in-front` or `@behind`. Such children render
1494// True if any direct child is `@in-front` or `@behind`. Such children render
1298// as absolutely positioned overlays, so the parent automatically becomes a
1495// as absolutely positioned overlays, so the parent automatically becomes a
1299// positioning context (position:relative + isolation:isolate).
1496// positioning context (position:relative + isolation:isolate).
1300fn has_overlay_children(elem: &Element) -> bool {
1497fn has_overlay_children(elem: &Element) -> bool {
1301− holds_overlays(&elem.children)
1304−fn holds_overlays(children: &[Node]) -> bool {
1305− children.iter().any(|child| {
1498+ elem.children.iter().any(|child| {
1306 matches!(
1499 matches!(
1308− Node::Element(e) if e.kind.is_tag("in-front") || e.kind.is_tag("behind")
1501+ Node::Element(e) if matches!(e.kind, ElementKind::InFront | ElementKind::Behind)
1313fn generate_element(
1506fn generate_element(
1314 elem: &Element,
1507 elem: &Element,
1315− parent: Option<Layout>,
1508+ parent_kind: Option<&ElementKind>,
1316 out: &mut String,
1509 out: &mut String,
1317 styles: &mut StyleCollector,
1510 styles: &mut StyleCollector,
1318 ctx: &mut GenContext,
1511 ctx: &mut GenContext,
1320 // Self-closing elements
1513 // Self-closing elements
1321− if elem.kind.layout() == Layout::Void {
1515+ elem.kind,
1517+ | ElementKind::Input
1518+ | ElementKind::HorizontalRule
1519+ | ElementKind::Source
1520+ | ElementKind::Spacer
1322− generate_self_closing(elem, parent, out, styles, ctx);
1522+ generate_self_closing(elem, parent_kind, out, styles, ctx);
1325− // A verbatim element (@script) writes its body as it is, with no HTML
1525+ // @script renders as <script> with raw body content (no HTML escaping)
1326− // escaping; it isn't shown, so it has no class (its styles are an error)
1327− if elem.kind.is_verbatim() {
1526+ if elem.kind == ElementKind::Script {
1328− let tag = elem.kind.spec().map_or("script", |spec| spec.html);
1329 out.push_str(&ctx.indent());
1527 out.push_str(&ctx.indent());
1330− out.push('<');
1528+ out.push_str("<script");
1331− out.push_str(tag);
1529+ // Pass through src, type, defer, async, etc.
1332− emit_argument_attr(out, elem, false);
1530+ for attr in &elem.attrs {
1333− let (id, class) = extract_id_class(&elem.attrs);
1531+ let key = attr.key.as_str();
1334− for (key, value) in [("id", id), ("class", class)] {
1532+ if matches!(
1335− if let Some(value) = value {
1533+ key,
1336− out.push_str(&format!(" {}=\"{}\"", key, html_escape(&value)));
1534+ "src"
1543+ if let Some(val) = &attr.value {
1546+ out.push_str("=\"");
1547+ out.push_str(&html_escape(val));
1339− emit_html_attrs(out, &elem.attrs);
1340 out.push('>');
1555 out.push('>');
1556+ // Children are raw JS code, not HTML
1341 for child in &elem.children {
1557 for child in &elem.children {
1342 match child {
1558 match child {
1343 Node::Text(segments) => {
1559 Node::Text(segments) => {
@@ -1351,10 +1567,46 @@ fn generate_element(
1354− out.push_str("</");
1570+ out.push_str("</script>");
1355− out.push_str(tag);
1571+ out.push_str(ctx.nl());
1574+ // @breadcrumb generates semantic <nav aria-label="breadcrumb"><ol>...</ol></nav>
1575+ if elem.kind == ElementKind::Breadcrumb {
1576+ let gen_class = compute_class(&elem.attrs, &elem.kind, parent_kind, styles, false);
1577+ let (id, user_class) = extract_id_class(&elem.attrs);
1578+ out.push_str(&ctx.indent());
1579+ out.push_str("<nav aria-label=\"breadcrumb\"");
1580+ emit_class_attr(out, gen_class.as_deref(), user_class.as_deref());
1581+ if let Some(id) = id {
1582+ out.push_str(" id=\"");
1583+ out.push_str(&html_escape(&id));
1356 out.push('>');
1586 out.push('>');
1357 out.push_str(ctx.nl());
1587 out.push_str(ctx.nl());
1589+ out.push_str(&ctx.indent());
1590+ out.push_str("<ol>");
1591+ out.push_str(ctx.nl());
1593+ for child in &elem.children {
1594+ out.push_str(&ctx.indent());
1595+ out.push_str("<li>");
1596+ let mut buf = String::new();
1597+ generate_node(child, Some(&elem.kind), &mut buf, styles, ctx);
1598+ out.push_str(buf.trim());
1599+ out.push_str("</li>");
1600+ out.push_str(ctx.nl());
1603+ out.push_str(&ctx.indent());
1604+ out.push_str("</ol>");
1605+ out.push_str(ctx.nl());
1607+ out.push_str(&ctx.indent());
1608+ out.push_str("</nav>");
1609+ out.push_str(ctx.nl());
1360 if elem.kind == ElementKind::Children {
1612 if elem.kind == ElementKind::Children {
@@ -1364,38 +1616,209 @@ fn generate_element(
1366 if elem.kind == ElementKind::Fragment {
1618 if elem.kind == ElementKind::Fragment {
1367− // Render children without a wrapper element, as if they were
1619+ // Render children without a wrapper element
1368− // written where the fragment is
1620+ for child in &elem.children {
1369− generate_children(&elem.children, parent, out, styles, ctx);
1621+ generate_node(child, parent_kind, out, styles, ctx);
1373− let mut own = Flow::of(elem);
1374 let tag = match &elem.kind {
1626 let tag = match &elem.kind {
1375− ElementKind::Row | ElementKind::El => "div",
1627+ ElementKind::Row
1628+ | ElementKind::Column
1630+ | ElementKind::Grid
1631+ | ElementKind::Stack
1632+ | ElementKind::InFront
1633+ | ElementKind::Behind => "div",
1376 ElementKind::Text => "span",
1634 ElementKind::Text => "span",
1377 ElementKind::Paragraph => "p",
1635 ElementKind::Paragraph => "p",
1378 ElementKind::Link => "a",
1636 ElementKind::Link => "a",
1379− ElementKind::Tag(spec) => spec.html,
1637+ ElementKind::Button => "button",
1638+ ElementKind::Select => "select",
1639+ ElementKind::Textarea => "textarea",
1640+ ElementKind::Option => "option",
1641+ ElementKind::Label => "label",
1642+ // Semantic elements
1643+ ElementKind::Nav => "nav",
1644+ ElementKind::Header => "header",
1645+ ElementKind::Footer => "footer",
1646+ ElementKind::Main => "main",
1647+ ElementKind::Section => "section",
1648+ ElementKind::Article => "article",
1649+ ElementKind::Aside => "aside",
1651+ ElementKind::List => {
1652+ if elem.attrs.iter().any(|a| a.key == "ordered") {
1658+ ElementKind::ListItem => "li",
1660+ ElementKind::Table => "table",
1661+ ElementKind::TableHead => "thead",
1662+ ElementKind::TableBody => "tbody",
1663+ ElementKind::TableRow => "tr",
1664+ ElementKind::TableCell => "td",
1665+ ElementKind::TableHeaderCell => "th",
1667+ ElementKind::Video => "video",
1668+ ElementKind::Audio => "audio",
1669+ // Additional semantic elements
1670+ ElementKind::Form => "form",
1671+ ElementKind::Details => "details",
1672+ ElementKind::Summary => "summary",
1673+ ElementKind::Blockquote => "blockquote",
1674+ ElementKind::Cite => "cite",
1675+ ElementKind::Code => "code",
1676+ ElementKind::Pre => "pre",
1677+ ElementKind::Figure => "figure",
1678+ ElementKind::FigCaption => "figcaption",
1679+ ElementKind::Progress => "progress",
1680+ ElementKind::Meter => "meter",
1682+ ElementKind::Dialog => "dialog",
1683+ ElementKind::DefinitionList => "dl",
1684+ ElementKind::DefinitionTerm => "dt",
1685+ ElementKind::DefinitionDescription => "dd",
1686+ ElementKind::Fieldset => "fieldset",
1687+ ElementKind::Legend => "legend",
1688+ ElementKind::Picture => "picture",
1689+ ElementKind::Time => "time",
1690+ ElementKind::Mark => "mark",
1691+ ElementKind::Kbd => "kbd",
1692+ ElementKind::Abbr => "abbr",
1693+ ElementKind::Datalist => "datalist",
1694+ ElementKind::Iframe => "iframe",
1695+ ElementKind::Output => "output",
1696+ ElementKind::Canvas => "canvas",
1697+ ElementKind::Badge => "span",
1698+ ElementKind::Tooltip => "span",
1699+ ElementKind::Avatar => "div",
1700+ ElementKind::Carousel => "div",
1701+ ElementKind::Chip => "span",
1702+ ElementKind::Tag => "span",
1703+ ElementKind::Noscript => "noscript",
1704+ ElementKind::Address => "address",
1705+ ElementKind::Search => "search",
1706+ // Heading elements
1707+ ElementKind::H1 => "h1",
1708+ ElementKind::H2 => "h2",
1709+ ElementKind::H3 => "h3",
1710+ ElementKind::H4 => "h4",
1711+ ElementKind::H5 => "h5",
1712+ ElementKind::H6 => "h6",
1714+ | ElementKind::Input
1715+ | ElementKind::HorizontalRule
1716+ | ElementKind::Children
1717+ | ElementKind::Slot(_)
1718+ | ElementKind::Fragment
1719+ | ElementKind::Source
1720+ | ElementKind::Spacer
1721+ | ElementKind::Script
1722+ | ElementKind::Breadcrumb => unreachable!(),
1725+ let kind_label = match elem.kind {
1726+ ElementKind::Row => "row",
1727+ ElementKind::Column => "column",
1728+ ElementKind::El => "el",
1729+ ElementKind::Text => "text",
1730+ ElementKind::Paragraph => "paragraph",
1731+ ElementKind::Link => "link",
1732+ ElementKind::Button => "button",
1733+ ElementKind::Select => "select",
1734+ ElementKind::Textarea => "textarea",
1735+ ElementKind::Option => "option",
1736+ ElementKind::Label => "label",
1737+ ElementKind::Nav => "nav",
1738+ ElementKind::Header => "header",
1739+ ElementKind::Footer => "footer",
1740+ ElementKind::Main => "main",
1741+ ElementKind::Section => "section",
1742+ ElementKind::Article => "article",
1743+ ElementKind::Aside => "aside",
1744+ ElementKind::List => "list",
1745+ ElementKind::ListItem => "item",
1746+ ElementKind::Table => "table",
1747+ ElementKind::TableHead => "thead",
1748+ ElementKind::TableBody => "tbody",
1749+ ElementKind::TableRow => "tr",
1750+ ElementKind::TableCell => "td",
1751+ ElementKind::TableHeaderCell => "th",
1752+ ElementKind::Video => "video",
1753+ ElementKind::Audio => "audio",
1754+ ElementKind::Form => "form",
1755+ ElementKind::Details => "details",
1756+ ElementKind::Summary => "summary",
1757+ ElementKind::Blockquote => "blockquote",
1758+ ElementKind::Cite => "cite",
1759+ ElementKind::Code => "code",
1760+ ElementKind::Pre => "pre",
1761+ ElementKind::Figure => "figure",
1762+ ElementKind::FigCaption => "figcaption",
1763+ ElementKind::Fragment => "fragment",
1764+ ElementKind::Dialog => "dialog",
1765+ ElementKind::DefinitionList => "dl",
1766+ ElementKind::DefinitionTerm => "dt",
1767+ ElementKind::DefinitionDescription => "dd",
1768+ ElementKind::Fieldset => "fieldset",
1769+ ElementKind::Legend => "legend",
1770+ ElementKind::Picture => "picture",
1771+ ElementKind::Time => "time",
1772+ ElementKind::Mark => "mark",
1773+ ElementKind::Kbd => "kbd",
1774+ ElementKind::Abbr => "abbr",
1775+ ElementKind::Datalist => "datalist",
1776+ ElementKind::Iframe => "iframe",
1777+ ElementKind::Output => "output",
1778+ ElementKind::Canvas => "canvas",
1779+ ElementKind::Grid => "grid",
1780+ ElementKind::Stack => "stack",
1781+ ElementKind::Badge => "badge",
1782+ ElementKind::Tooltip => "tooltip",
1783+ ElementKind::Avatar => "avatar",
1784+ ElementKind::Carousel => "carousel",
1785+ ElementKind::Chip => "chip",
1786+ ElementKind::Tag => "tag",
1787+ ElementKind::Noscript => "noscript",
1788+ ElementKind::Address => "address",
1789+ ElementKind::Search => "search",
1790+ ElementKind::InFront => "in-front",
1791+ ElementKind::Behind => "behind",
1792+ ElementKind::H1 => "h1",
1793+ ElementKind::H2 => "h2",
1794+ ElementKind::H3 => "h3",
1795+ ElementKind::H4 => "h4",
1796+ ElementKind::H5 => "h5",
1797+ ElementKind::H6 => "h6",
1380 _ => "",
1798 _ => "",
1382− // Inside text, htmlang's own `<div>` is a `<span>`, which text can
1383− // hold (directly in text, a row, column or grid is also laid out
1384− // inline: see `Site::inline`)
1385− let in_text = ctx.in_text || parent == Some(Layout::Text);
1386− let tag = if in_text && tag == "div" { "span" } else { tag };
1387− let kind_label = elem.kind.name();
1389 // Track interactive elements for focus-visible CSS
1801 // Track interactive elements for focus-visible CSS
1390− if elem.kind == ElementKind::Link
1802+ if matches!(
1391− || matches!(kind_label, "button" | "input" | "select" | "textarea")
1803+ elem.kind,
1392− {
1804+ ElementKind::Link
1805+ | ElementKind::Button
1806+ | ElementKind::Input
1807+ | ElementKind::Select
1808+ | ElementKind::Textarea
1393 ctx.has_interactive = true;
1810 ctx.has_interactive = true;
1396 // Compute CSS for each state and get a class name
1813 // Compute CSS for each state and get a class name
1397− let gen_class = element_class(elem, &Site::new(elem, parent, &ctx.flow), styles);
1814+ let overlay_children = has_overlay_children(elem);
1398− own.class = gen_class.clone();
1815+ let gen_class = compute_class(
1399 let (id, user_class) = extract_id_class(&elem.attrs);
1822 let (id, user_class) = extract_id_class(&elem.attrs);
1401 if ctx.dev && elem.line_num > 0 {
1824 if ctx.dev && elem.line_num > 0 {
@@ -1409,48 +1832,133 @@ fn generate_element(
1409 out.push('<');
1832 out.push('<');
1410 out.push_str(tag);
1833 out.push_str(tag);
1412− emit_argument_attr(out, elem, ctx.in_picture);
1835+ // @main gets id="hl-main" for skip-to-content link (unless user set an id)
1836+ if elem.kind == ElementKind::Main && id.is_none() {
1837+ out.push_str(" id=\"hl-main\"");
1414− emit_class_attr(out, gen_class.as_deref(), user_class.as_deref());
1840+ if elem.kind == ElementKind::Link
1841+ && let Some(url) = &elem.argument
1843+ out.push_str(" href=\"");
1844+ out.push_str(&html_escape(url));
1846+ // Auto rel="noopener noreferrer" and target="_blank" for external links
1847+ let is_external = url.starts_with("http://") || url.starts_with("https://");
1849+ let has_rel = elem.attrs.iter().any(|a| a.key == "rel");
1850+ let has_target = elem.attrs.iter().any(|a| a.key == "target");
1852+ out.push_str(" rel=\"noopener noreferrer\"");
1855+ out.push_str(" target=\"_blank\"");
1416− if let Some(id) = id {
1860+ // Video/Audio src
1417− out.push_str(" id=\"");
1861+ if matches!(elem.kind, ElementKind::Video | ElementKind::Audio)
1418− out.push_str(&html_escape(&id));
1862+ && let Some(src) = &elem.argument
1864+ out.push_str(" src=\"");
1865+ out.push_str(&html_escape(src));
1419 out.push('"');
1866 out.push('"');
1422− emit_html_attrs(out, &elem.attrs);
1869+ // Form action
1870+ if elem.kind == ElementKind::Form
1871+ && let Some(action) = &elem.argument
1873+ out.push_str(" action=\"");
1874+ out.push_str(&html_escape(action));
1424− // Source map attributes in dev mode
1878+ // Iframe src
1425− if ctx.dev && elem.line_num > 0 {
1879+ if elem.kind == ElementKind::Iframe
1426− out.push_str(&format!(
1880+ && let Some(src) = &elem.argument
1427− " data-hl-line=\"{}\" data-hl-el=\"{}\"",
1881+ {
1428− elem.line_num, kind_label
1882+ out.push_str(" src=\"");
1429− ));
1883+ out.push_str(&html_escape(src));
1432− out.push('>');
1887+ // Tooltip title
1433− // In `<pre>` and `<textarea>` every space and line break shows, so
1888+ if elem.kind == ElementKind::Tooltip
1434− // readable (dev) output adds none there: a code sample's lines stay
1889+ && let Some(text) = &elem.argument
1435− // exactly as written
1890+ {
1436− let outer_dev = ctx.dev;
1891+ out.push_str(" title=\"");
1437− ctx.dev &= !matches!(tag, "pre" | "textarea");
1892+ out.push_str(&html_escape(text));
1438− out.push_str(ctx.nl());
1893+ out.push('"');
1440− let layout = elem.kind.layout();
1896+ // Critical CSS: inline styles directly instead of using a class
1441− ctx.depth += 1;
1897+ let is_critical = elem.attrs.iter().any(|a| a.key == "critical");
1442− let outer_in_text = ctx.in_text;
1898+ if is_critical {
1443− ctx.in_text = in_text || layout == Layout::Text;
1899+ let inline_css = attrs_to_css(&elem.attrs, "", &elem.kind, parent_kind, overlay_children);
1444− let outer_flow = std::mem::replace(&mut ctx.flow, own);
1900+ if !inline_css.is_empty() {
1445− let outer_picture = std::mem::replace(&mut ctx.in_picture, elem.kind.is_tag("picture"));
1901+ out.push_str(" style=\"");
1446− generate_children(&elem.children, Some(layout), out, styles, ctx);
1902+ out.push_str(&html_escape(&inline_css));
1447− ctx.in_picture = outer_picture;
1903+ out.push('"');
1448− ctx.flow = outer_flow;
1904+ }
1449− ctx.in_text = outer_in_text;
1905+ // Still use class for non-base styles (pseudo, responsive, etc.)
1906+ if gen_class.as_deref().is_some_and(|c| !c.is_empty()) {
1907+ emit_class_attr(out, gen_class.as_deref(), user_class.as_deref());
1908+ } else if let Some(ref uc) = user_class {
1909+ emit_class_attr(out, None, Some(uc));
1912+ emit_class_attr(out, gen_class.as_deref(), user_class.as_deref());
1915+ if let Some(id) = id {
1916+ out.push_str(" id=\"");
1917+ out.push_str(&html_escape(&id));
1921+ emit_html_passthrough_attrs(out, &elem.attrs);
1923+ // Source map attributes in dev mode
1924+ if ctx.dev && elem.line_num > 0 {
1925+ out.push_str(&format!(
1926+ " data-hl-line=\"{}\" data-hl-el=\"{}\"",
1927+ elem.line_num, kind_label
1932+ out.push_str(ctx.nl());
1934+ // Inline text argument
1935+ if renders_argument_as_text(&elem.kind)
1936+ && let Some(text) = &elem.argument
1938+ out.push_str(&html_escape(text));
1943+ let is_paragraph = matches!(
1945+ ElementKind::Paragraph
1953+ for (i, child) in elem.children.iter().enumerate() {
1954+ generate_node(child, Some(&elem.kind), out, styles, ctx);
1955+ if is_paragraph && i < elem.children.len() - 1 {
1450 ctx.depth -= 1;
1959 ctx.depth -= 1;
1452 out.push_str(&ctx.indent());
1961 out.push_str(&ctx.indent());
1453− ctx.dev = outer_dev;
1454 out.push_str("</");
1962 out.push_str("</");
1455 out.push_str(tag);
1963 out.push_str(tag);
1456 out.push('>');
1964 out.push('>');
@@ -1459,18 +1967,21 @@ fn generate_element(
1460fn generate_self_closing(
1968fn generate_self_closing(
1461 elem: &Element,
1969 elem: &Element,
1462− parent: Option<Layout>,
1970+ parent_kind: Option<&ElementKind>,
1463 out: &mut String,
1971 out: &mut String,
1464 styles: &mut StyleCollector,
1972 styles: &mut StyleCollector,
1465 ctx: &mut GenContext,
1973 ctx: &mut GenContext,
1467− let gen_class = element_class(elem, &Site::new(elem, parent, &ctx.flow), styles);
1975+ let gen_class = compute_class(&elem.attrs, &elem.kind, parent_kind, styles, false);
1468 let (id, user_class) = extract_id_class(&elem.attrs);
1976 let (id, user_class) = extract_id_class(&elem.attrs);
1470− let (tag, kind_label) = match &elem.kind {
1978+ let (tag, kind_label) = match elem.kind {
1471 ElementKind::Image => ("img", "image"),
1979 ElementKind::Image => ("img", "image"),
1472− ElementKind::Tag(spec) => (spec.html, spec.name),
1980+ ElementKind::Input => ("input", "input"),
1473− _ => unreachable!("not a void element: {:?}", elem.kind),
1981+ ElementKind::HorizontalRule => ("hr", "hr"),
1982+ ElementKind::Source => ("source", "source"),
1983+ ElementKind::Spacer => ("div", "spacer"),
1984+ _ => unreachable!(),
1476 if ctx.dev && elem.line_num > 0 {
1987 if ctx.dev && elem.line_num > 0 {
@@ -1483,7 +1994,43 @@ fn generate_self_closing(
1483 out.push_str(&ctx.indent());
1994 out.push_str(&ctx.indent());
1484 out.push('<');
1995 out.push('<');
1485 out.push_str(tag);
1996 out.push_str(tag);
1486− emit_argument_attr(out, elem, ctx.in_picture);
1997+
1998+ // Image src (with optional non-SVG base64 inlining)
1999+ if elem.kind == ElementKind::Image {
2000+ let src = elem.argument.as_deref().unwrap_or("");
2001+ let is_inline = elem.attrs.iter().any(|a| a.key == "inline");
2002+ if is_inline && !src.is_empty() && !src.ends_with(".svg") {
2003+ let mime = if src.ends_with(".png") {
2005+ } else if src.ends_with(".jpg") || src.ends_with(".jpeg") {
2007+ } else if src.ends_with(".gif") {
2009+ } else if src.ends_with(".webp") {
2011+ } else if src.ends_with(".avif") {
2014+ "application/octet-stream"
2016+ if let Ok(data) = std::fs::read(src) {
2017+ let b64 = base64_encode(&data);
2018+ out.push_str(" src=\"data:");
2019+ out.push_str(mime);
2020+ out.push_str(";base64,");
2021+ out.push_str(&b64);
2024+ out.push_str(" src=\"");
2025+ out.push_str(&html_escape(src));
2029+ out.push_str(" src=\"");
2030+ out.push_str(&html_escape(src));
1488 emit_class_attr(out, gen_class.as_deref(), user_class.as_deref());
2035 emit_class_attr(out, gen_class.as_deref(), user_class.as_deref());
@@ -1493,7 +2040,7 @@ fn generate_self_closing(
1493 out.push('"');
2040 out.push('"');
1496− emit_html_attrs(out, &elem.attrs);
2043+ emit_html_passthrough_attrs(out, &elem.attrs);
1498 // Source map attributes in dev mode (self-closing)
2045 // Source map attributes in dev mode (self-closing)
1499 if ctx.dev && elem.line_num > 0 {
2046 if ctx.dev && elem.line_num > 0 {
@@ -1503,6 +2050,93 @@ fn generate_self_closing(
2053+ // Image optimization: auto-add loading="lazy" and decoding="async"
2054+ if elem.kind == ElementKind::Image {
2055+ // SVG inlining: @image [inline] logo.svg
2056+ if elem.attrs.iter().any(|a| a.key == "inline")
2057+ && let Some(src) = &elem.argument
2058+ && src.ends_with(".svg")
2059+ && let Ok(svg_content) = std::fs::read_to_string(src)
2061+ // Close the tag we opened, then emit inline SVG instead
2062+ out.truncate(out.rfind('<').unwrap_or(0));
2063+ out.push_str(&ctx.indent());
2064+ out.push_str(svg_content.trim());
2065+ out.push_str(ctx.nl());
2068+ // Responsive srcset: @image photo.jpg [responsive 400 800 1200]
2069+ let responsive_attr = elem.attrs.iter().find(|a| a.key == "responsive");
2070+ if let Some(resp) = responsive_attr
2071+ && let Some(ref sizes_str) = resp.value
2073+ let widths: Vec<&str> = sizes_str.split_whitespace().collect();
2074+ if !widths.is_empty() {
2075+ let src = elem.argument.as_deref().unwrap_or("");
2076+ if !src.is_empty() {
2077+ // Generate srcset with width descriptors
2078+ // Convention: file-{width}.ext (e.g., photo-400.jpg)
2079+ let dot_pos = src.rfind('.').unwrap_or(src.len());
2080+ let base = &src[..dot_pos];
2081+ let ext = &src[dot_pos..];
2082+ let mut srcset_parts = Vec::new();
2084+ srcset_parts.push(format!("{}-{}{} {}w", base, w, ext, w));
2086+ out.push_str(" srcset=\"");
2087+ out.push_str(&srcset_parts.join(", "));
2089+ // Generate sizes attribute
2090+ let max_width = widths.last().unwrap_or(&"100vw");
2091+ out.push_str(&format!(
2092+ " sizes=\"(max-width: {}px) 100vw, {}px\"",
2093+ max_width, max_width
2099+ // Auto image dimensions: read local image file to inject width/height + aspect-ratio
2100+ let has_width = elem.attrs.iter().any(|a| a.key == "width");
2101+ let has_height = elem.attrs.iter().any(|a| a.key == "height");
2102+ if (!has_width || !has_height)
2103+ && let Some(ref src) = elem.argument
2104+ && !src.starts_with("http://")
2105+ && !src.starts_with("https://")
2106+ && !src.starts_with("data:")
2107+ && let Some((w, h)) = read_image_dimensions(src)
2109+ // Intrinsic size attributes only when neither dimension is set in
2110+ // CSS; with one CSS dimension, a leftover intrinsic attribute for
2111+ // the other would distort the image (200 wide but 1000 tall).
2112+ if !has_width && !has_height {
2113+ out.push_str(&format!(" width=\"{}\" height=\"{}\"", w, h));
2115+ // Auto aspect-ratio to prevent CLS
2116+ if !elem.attrs.iter().any(|a| a.key == "aspect-ratio") {
2117+ out.push_str(&format!(" style=\"aspect-ratio:{}/{}\"", w, h));
2121+ // Smart image loading: first 3 images get fetchpriority="high" (above the fold),
2122+ // subsequent images get loading="lazy" + decoding="async"
2123+ ctx.image_count += 1;
2124+ if ctx.image_count <= 3 {
2125+ // Above-the-fold: eager loading with high priority
2126+ if !elem.attrs.iter().any(|a| a.key == "fetchpriority") {
2127+ out.push_str(" fetchpriority=\"high\"");
2130+ // Below-the-fold: lazy loading
2131+ if !elem.attrs.iter().any(|a| a.key == "loading") {
2132+ out.push_str(" loading=\"lazy\"");
2134+ if !elem.attrs.iter().any(|a| a.key == "decoding") {
2135+ out.push_str(" decoding=\"async\"");
1506 out.push('>');
2140 out.push('>');
1507 out.push_str(ctx.nl());
2141 out.push_str(ctx.nl());
@@ -1518,10 +2152,7 @@ fn generate_text_segments(
1518 TextSegment::Plain(text) => out.push_str(&html_escape(text)),
2152 TextSegment::Plain(text) => out.push_str(&html_escape(text)),
1519 TextSegment::Inline(elem) => {
2153 TextSegment::Inline(elem) => {
1520 let mut buf = String::new();
2154 let mut buf = String::new();
1521− // An element inside a line of text is in text
2155+ generate_element(elem, None, &mut buf, styles, ctx);
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;
1525 out.push_str(buf.trim_end());
2156 out.push_str(buf.trim_end());
@@ -1534,97 +2165,143 @@ fn generate_text_segments(
1535fn compute_class(
2166fn compute_class(
1536 attrs: &[Attribute],
2167 attrs: &[Attribute],
1537− site: &Site,
2168+ kind: &ElementKind,
2169+ parent_kind: Option<&ElementKind>,
1538 styles: &mut StyleCollector,
2170 styles: &mut StyleCollector,
1539− distinct: String,
2171+ has_overlay_children: bool,
1540) -> Option<String> {
2172) -> Option<String> {
1541− // Every condition an attribute is under, and none
2173+ let base = attrs_to_css(attrs, "", kind, parent_kind, has_overlay_children);
1542− let mut conditions = vec![Condition::default()];
2174+
1543− for attr in attrs.iter().filter(|a| !a.html) {
2175+ // Collect pseudo-state overrides
1544− let (condition, _) = Condition::of(&attr.key);
2176+ let mut pseudo = Vec::new();
1545− if !conditions.contains(&condition) {
2177+ for &(prefix, selector) in PSEUDO_PREFIXES {
1546− conditions.push(condition);
2178+ let css = attrs_to_css(attrs, prefix, kind, parent_kind, has_overlay_children);
2179+ if !css.is_empty() {
2180+ pseudo.push((selector.to_string(), css));
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
1554− let css = dedupe_declarations(&attrs_to_css(attrs, &condition, site));
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)
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)
1570− styles.get_class(defaults, rules, distinct)
1573−/// The defaults of an element's kind where it is: an overlay's positioning
2184+ // Auto-add ::-webkit-scrollbar pseudo for no-scrollbar attribute
1574−/// context, its layout, and its kind's own CSS (a heading's `margin:0`).
2185+ if attrs.iter().any(|a| a.key == "no-scrollbar") {
1575−fn default_css(site: &Site) -> String {
2186+ pseudo.push((
1576− let mut css = String::new();
2187+ "::-webkit-scrollbar".to_string(),
1577− // Elements with @in-front / @behind children become positioning
2188+ "display:none;".to_string(),
1578− // contexts
2189+ ));
1579− if site.has_overlay_children {
1580− css.push_str("position:relative;isolation:isolate;");
1583− css.push_str(layout_css(site.kind.layout(), site.inline));
1585− css.push_str(site.kind.css());
1589−/// The declarations of a rule body, as (property, `property:value;`), for
2192+ // Collect nth:EXPR: dynamic pseudo selectors
1590−/// bodies htmlang wrote: every declaration ends in `;`, and a `;` inside
2193+ let mut nth_prefixes: Vec<String> = Vec::new();
1591−/// quotes or parentheses doesn't end one.
2194+ for attr in attrs {
1592−fn declarations(css: &str) -> impl Iterator<Item = (&str, &str)> {
2195+ if attr.key.starts_with("nth:") {
1593− let mut rest = css;
2196+ let rest = &attr.key[4..];
1594− std::iter::from_fn(move || {
2197+ if let Some(colon_pos) = rest.find(':') {
1595− if rest.is_empty() {
2198+ let prefix = format!("nth:{}:", &rest[..colon_pos]);
1596− return None;
2199+ if !nth_prefixes.contains(&prefix) {
1597− }
2200+ nth_prefixes.push(prefix);
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() {
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),
1609− ';' if depth == 0 => {
1616− let (declaration, after) = rest.split_at(end);
2204+ }
1617− rest = after;
2205+ for prefix in &nth_prefixes {
1618− let name = declaration.split(':').next().unwrap_or("").trim();
2206+ let expr = &prefix[4..prefix.len() - 1];
1619− Some((name, declaration))
2207+ let selector = format!(":nth-child({})", expr);
1620− })
2208+ let css = attrs_to_css(attrs, prefix, kind, parent_kind, has_overlay_children);
2209+ if !css.is_empty() {
2210+ pseudo.push((selector, css));
2214+ // Collect has(...): dynamic pseudo selectors
2215+ let mut has_prefixes: Vec<String> = Vec::new();
2216+ for attr in attrs {
2217+ if attr.key.starts_with("has(")
2218+ && let Some(close) = attr.key.find("):")
2220+ let prefix = format!("{}:", &attr.key[..close + 1]);
2221+ if !has_prefixes.contains(&prefix) {
2222+ has_prefixes.push(prefix);
2226+ for prefix in &has_prefixes {
2227+ let inner = &prefix[4..prefix.len() - 2]; // extract selector from has(selector):
2228+ let selector = format!(":has({})", inner);
2229+ let css = attrs_to_css(attrs, prefix, kind, parent_kind, has_overlay_children);
2230+ if !css.is_empty() {
2231+ pseudo.push((selector, css));
2235+ // Collect responsive overrides
2236+ let mut responsive = Vec::new();
2237+ for &(bp_name, _) in BREAKPOINTS {
2238+ let prefix = format!("{}:", bp_name);
2239+ let css = attrs_to_css(attrs, &prefix, kind, parent_kind, has_overlay_children);
2240+ if !css.is_empty() {
2241+ responsive.push((bp_name.to_string(), css));
2245+ // Collect container query overrides
2246+ let mut container = Vec::new();
2247+ for &(bp_name, _) in BREAKPOINTS {
2248+ let prefix = format!("cq-{}:", bp_name);
2249+ let css = attrs_to_css(attrs, &prefix, kind, parent_kind, has_overlay_children);
2250+ if !css.is_empty() {
2251+ container.push((bp_name.to_string(), css));
2255+ let dark = attrs_to_css(attrs, "dark:", kind, parent_kind, has_overlay_children);
2256+ let print = attrs_to_css(attrs, "print:", kind, parent_kind, has_overlay_children);
2257+ let motion_safe = attrs_to_css(attrs, "motion-safe:", kind, parent_kind, has_overlay_children);
2258+ let motion_reduce =
2259+ attrs_to_css(attrs, "motion-reduce:", kind, parent_kind, has_overlay_children);
2260+ let landscape = attrs_to_css(attrs, "landscape:", kind, parent_kind, has_overlay_children);
2261+ let portrait = attrs_to_css(attrs, "portrait:", kind, parent_kind, has_overlay_children);
2263+ // Dedupe: if a property is declared twice within a single rule, keep only
2264+ // the last occurrence (element-kind defaults are written before
2265+ // user attributes, so a user [list-style disc] correctly overrides the
2266+ // default list-style:none, and we don't need to ship both).
2267+ let base = dedupe_declarations(&base);
2268+ let pseudo: Vec<(String, String)> = pseudo
2270+ .map(|(sel, css)| (sel, dedupe_declarations(&css)))
2272+ let responsive: Vec<(String, String)> = responsive
2274+ .map(|(bp, css)| (bp, dedupe_declarations(&css)))
2276+ let dark = dedupe_declarations(&dark);
2277+ let print = dedupe_declarations(&print);
2278+ let motion_safe = dedupe_declarations(&motion_safe);
2279+ let motion_reduce = dedupe_declarations(&motion_reduce);
2280+ let landscape = dedupe_declarations(&landscape);
2281+ let portrait = dedupe_declarations(&portrait);
2282+ let container: Vec<(String, String)> = container
2284+ .map(|(bp, css)| (bp, dedupe_declarations(&css)))
1623/// Dedupe CSS declarations within a single rule body: for any property
2301/// Dedupe CSS declarations within a single rule body: for any property
1624/// declared more than once, keep only the last occurrence. Unparseable
2302/// declared more than once, keep only the last occurrence. Unparseable
1625−/// segments (no `:`) are preserved as-is. Semicolons inside parentheses or
2303+/// segments (no `:`) are preserved as-is. Semicolons inside parentheses are
1626−/// quoted strings are treated as part of a value, not as declaration
2304+/// treated as part of a value, not as declaration separators.
1628fn dedupe_declarations(css: &str) -> String {
2305fn dedupe_declarations(css: &str) -> String {
1629 if css.is_empty() {
2306 if css.is_empty() {
1630 return String::new();
2307 return String::new();
@@ -1639,26 +2316,8 @@ fn dedupe_declarations(css: &str) -> String {
1639 let mut decls: Vec<(Option<String>, String)> = Vec::new();
2316 let mut decls: Vec<(Option<String>, String)> = Vec::new();
1640 let mut current = String::new();
2317 let mut current = String::new();
1641 let mut depth: i32 = 0;
2318 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;
1646 for ch in css.chars() {
2319 for ch in css.chars() {
1647− if escaped {
2320+ if ch == '(' {
1650− } else if ch == '\\' {
1653− } else if let Some(q) = quote {
1658− } else if ch == '"' || ch == '\'' {
1661− } else if ch == '(' {
1662 depth += 1;
2321 depth += 1;
1663 current.push(ch);
2322 current.push(ch);
1664 } else if ch == ')' {
2323 } else if ch == ')' {
@@ -1740,578 +2399,1268 @@ fn emit_class_attr(out: &mut String, gen_class: Option<&str>, user_class: Option
1740// Attribute → CSS mapping
2399// Attribute → CSS mapping
1741// ---------------------------------------------------------------------------
2400// ---------------------------------------------------------------------------
1743−/// Where an element is written, which its CSS depends on.
2402+/// (htmlang prefix, CSS selector suffix)
1744−struct Site<'a> {
2403+const PSEUDO_PREFIXES: &[(&str, &str)] = &[
1745− kind: &'a ElementKind,
2404+ ("hover:", ":hover"),
1746− /// How its parent lays out its children: its `width fill`, `height
2405+ ("active:", ":active"),
1747− /// fill` and `shrink` compile against it.
2406+ ("focus:", ":focus"),
1748− parent: &'a Flow,
2407+ ("focus-visible:", ":focus-visible"),
1749− /// It has `@in-front` / `@behind` children.
2408+ ("focus-within:", ":focus-within"),
1750− has_overlay_children: bool,
2409+ ("disabled:", ":disabled"),
1751− /// A row, column or grid inside text, laid out inline.
2410+ ("checked:", ":checked"),
1752− inline: bool,
2411+ ("placeholder:", "::placeholder"),
1753− /// The page's `<body>`, which the reset already makes a column.
2412+ ("first:", ":first-child"),
1754− root: bool,
2413+ ("last:", ":last-child"),
1755−}
2414+ ("odd:", ":nth-child(odd)"),
1756−
2415+ ("even:", ":nth-child(even)"),
1757−impl Site<'_> {
2416+ ("before:", "::before"),
1758− /// Where an element in a parent with the layout `layout` and the flow
2417+ ("after:", "::after"),
1759− /// `parent` is.
2418+ ("selection:", "::selection"),
1760− fn new<'a>(elem: &'a Element, layout: Option<Layout>, parent: &'a Flow) -> Site<'a> {
2419+ ("visited:", ":visited"),
1761− Site {
2420+ ("empty:", ":empty"),
1762− kind: &elem.kind,
2421+ ("target:", ":target"),
1763− parent,
2422+ ("valid:", ":valid"),
1764− has_overlay_children: has_overlay_children(elem),
2423+ ("invalid:", ":invalid"),
1765− inline: layout == Some(Layout::Text) && elem.kind.layout().is_container(),
2424+];
1766− root: false,
2425+const RESPONSIVE_PREFIXES: &[&str] = &["sm:", "md:", "lg:", "xl:", "2xl:"];
1767− }
2426+const MEDIA_PREFIXES: &[&str] = &[
2434+const CONTAINER_QUERY_PREFIXES: &[&str] = &["cq-sm:", "cq-md:", "cq-lg:", "cq-xl:", "cq-2xl:"];
2436+fn is_prefixed_attr(key: &str) -> bool {
2437+ PSEUDO_PREFIXES.iter().any(|&(p, _)| key.starts_with(p))
2438+ || RESPONSIVE_PREFIXES.iter().any(|p| key.starts_with(p))
2439+ || MEDIA_PREFIXES.iter().any(|p| key.starts_with(p))
2440+ || CONTAINER_QUERY_PREFIXES.iter().any(|p| key.starts_with(p))
2441+ || key.starts_with("nth:")
2442+ || key.starts_with("has(")
1771−// ---------------------------------------------------------------------------
2445+/// `display:flex;flex-direction:column;` — base layout for `@el` and every
1772−// Direction: what a child's `fill` and `shrink` compile against
2446+/// semantic wrapper that behaves like a column.
1773−// ---------------------------------------------------------------------------
2447+const FLEX_COLUMN: &str = "display:flex;flex-direction:column;";
1775−/// The way a flex row or column lays out its children.
2449+/// Font stack shared by `@pre`, `@code`, `@kbd`.
1776−#[derive(Clone, Copy, PartialEq, Eq, Debug)]
2450+const MONOSPACE_STACK: &str = "font-family:ui-monospace,monospace;";
1782−impl Axis {
2452+/// Declarations common to `@badge` and `@tag`. They differ only in
1783− /// The direction a `flex-direction` or `flex-flow` value sets, if it
2453+/// `border-radius` (and `@badge` additionally centers content / pins
1784− /// names one (not `var(--dir)`, which only the browser knows).
2454+/// line-height:1), so keeping the shared base here avoids drift.
1785− fn of_value(value: &str) -> Option<Axis> {
2455+const PILL_BASE: &str =
1786− value.split_whitespace().find_map(|word| match word {
2456+ "display:inline-flex;align-items:center;padding:2px 8px;font-size:0.75rem;font-weight:600;";
1787− "row" | "row-reverse" => Some(Axis::Row),
1788− "column" | "column-reverse" => Some(Axis::Column),
1794−/// How an element lays out its children, as its CSS sets it: the
2458+fn attrs_to_css(
1795−/// direction its children's `width`/`height` `fill` and `shrink` compile
2459+ attrs: &[Attribute],
1796−/// against. That is the direction of `@row` or of a column, or the one its
2460+ state_prefix: &str,
1797−/// own `flex-direction` (or `flex-flow`) sets, with or without media or
2461+ kind: &ElementKind,
1798−/// container prefixes. Like elm-ui's `.r > .wf`, the rules for a direction
2462+ parent_kind: Option<&ElementKind>,
1799−/// set under a prefix are keyed on the element's class: `@media (...) {
2463+ has_overlay_children: bool,
1800−/// :where(.a)>.b {...} }`.
2464+) -> String {
1801−#[derive(Clone, Default)]
2465+ let mut css = String::new();
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
1811− class: Option<String>,
1814−impl Flow {
2467+ // Base element styles only for the default (non-state) pass
1815− fn of(elem: &Element) -> Flow {
2468+ if state_prefix.is_empty() {
1816− let mut base = match elem.kind.layout() {
2469+ // Elements with @in-front / @behind children become positioning
1817− Layout::Row => Axis::Row,
2470+ // contexts. Pushed before user attrs so an explicit `position` wins
1818− Layout::Column => Axis::Column,
2471+ // via dedupe (only the last declaration of a property is kept).
1819− _ => return Flow::default(),
2472+ if has_overlay_children {
1820− };
2473+ css.push_str("position:relative;isolation:isolate;");
1821− let mut changes: Vec<(Vec<usize>, Axis)> = Vec::new();
2474+ }
1822− for attr in elem.attrs.iter().filter(|a| !a.html) {
2475+ match kind {
1823− let (condition, name) = Condition::of(&attr.key);
2476+ ElementKind::Row => css.push_str("display:flex;flex-direction:row;"),
1824− if !matches!(name, "flex-direction" | "flex-flow") || !condition.selector.is_empty() {
2477+ ElementKind::Column
1825− continue;
2478+ | ElementKind::El
2479+ // Semantic elements get flex column layout like @el
2481+ | ElementKind::Header
2482+ | ElementKind::Footer
2483+ | ElementKind::Main
2484+ | ElementKind::Section
2485+ | ElementKind::Article
2486+ | ElementKind::Aside
2487+ | ElementKind::ListItem
2488+ | ElementKind::Form
2489+ | ElementKind::Details
2490+ | ElementKind::Dialog => css.push_str(FLEX_COLUMN),
2491+ ElementKind::Paragraph
2497+ | ElementKind::H6 => css.push_str("margin:0;"),
2498+ // Lists: reset browser defaults
2499+ ElementKind::List => css.push_str("margin:0;padding-left:0;list-style:none;"),
2500+ // Figure / Blockquote: flex column with browser margin reset
2501+ ElementKind::Figure | ElementKind::Blockquote => {
2502+ css.push_str(FLEX_COLUMN);
2503+ css.push_str("margin:0;");
1827− let Some(axis) = attr.value.as_deref().and_then(Axis::of_value) else {
2505+ // Pre: preserve whitespace
1828− continue;
2506+ ElementKind::Pre => {
1829− };
2507+ css.push_str("margin:0;white-space:pre;");
1830− if condition.at.is_empty() {
2508+ css.push_str(MONOSPACE_STACK);
1833− // The later one wins, as in the CSS
1834− changes.retain(|(at, _)| *at != condition.at);
1835− changes.push((condition.at, axis));
2510+ // Code / Kbd: monospace font
2511+ ElementKind::Code | ElementKind::Kbd => css.push_str(MONOSPACE_STACK),
2512+ ElementKind::DefinitionList => css.push_str("margin:0;"),
2513+ ElementKind::DefinitionDescription => {
2514+ css.push_str("margin:0;");
2515+ css.push_str(FLEX_COLUMN);
2517+ ElementKind::Fieldset => {
2518+ css.push_str(FLEX_COLUMN);
2519+ // Align padding to the px-based scale used by Badge/Tag/Chip
2520+ // rather than the old 0.5em (which depended on font-size).
2521+ css.push_str("border:1px solid currentColor;padding:8px;margin:0;");
2523+ ElementKind::Grid => css.push_str("display:grid;"),
2524+ ElementKind::Stack => css.push_str("position:relative;"),
2525+ ElementKind::Badge => {
2526+ css.push_str(PILL_BASE);
2527+ css.push_str("justify-content:center;border-radius:9999px;line-height:1;");
2529+ ElementKind::Tag => {
2530+ css.push_str(PILL_BASE);
2531+ css.push_str("border-radius:4px;");
2533+ ElementKind::Tooltip => css.push_str("position:relative;cursor:help;"),
2534+ ElementKind::Spacer => css.push_str("flex:1;"),
2535+ ElementKind::Avatar => css.push_str("display:inline-flex;align-items:center;justify-content:center;border-radius:9999px;overflow:hidden;flex-shrink:0;"),
2536+ ElementKind::Carousel => css.push_str("display:flex;flex-direction:row;overflow-x:auto;scroll-snap-type:x mandatory;-webkit-overflow-scrolling:touch;scrollbar-width:none;"),
2537+ ElementKind::Chip => css.push_str("display:inline-flex;align-items:center;gap:4px;padding:4px 12px;border-radius:9999px;font-size:0.875rem;border:1px solid currentColor;"),
2538+ // Overlay layers fill the parent. Parent gets position:relative
2539+ // applied automatically (see has_overlay_children check below).
2540+ ElementKind::InFront => {
2541+ css.push_str(FLEX_COLUMN);
2542+ css.push_str("position:absolute;inset:0;");
2544+ ElementKind::Behind => {
2545+ css.push_str(FLEX_COLUMN);
2546+ css.push_str("position:absolute;inset:0;z-index:-1;");
1838− changes.sort_by_key(|(at, _)| at_order(at));
2550+ // Children of @carousel get scroll-snap-align and flex-shrink
1839− Flow {
2551+ if matches!(parent_kind, Some(ElementKind::Carousel)) {
1840− base: Some(base),
2552+ css.push_str("scroll-snap-align:start;flex-shrink:0;");
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);
1856− .find(|(chain, _)| Condition::at_only(chain).holds_at(&here))
1857− .map(|&(_, axis)| axis);
1858− Some(changed.unwrap_or(base))
1862−/// `width` or `height`.
1863−#[derive(Clone, Copy, PartialEq, Eq)]
1869−/// What a `width` or `height` says.
1870−#[derive(Clone, Copy, PartialEq, Eq)]
1874− /// A size of its own (`width 300`)
1879− fn of(value: &str) -> Size {
1880− match value.trim() {
1881− "fill" => Size::Fill,
1882− "shrink" => Size::Shrink,
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
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")],
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] {
1912− ("flex", "0 1 auto"),
1913− ("min-width", "auto"),
1917− ("flex", "0 1 auto"),
1918− ("min-height", "auto"),
1919− ("height", "auto"),
1924−/// What an element's attributes under some prefixes say about its size.
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)
1934− /// It writes `flex`, one of its longhands (`flex-grow`, `flex-shrink`,
1935− /// `flex-basis`), `min-width` or `min-height` itself
1944−impl Sizes {
2556+ for attr in attrs {
1945− /// Read the attributes under the conditions that hold wherever `at`
2557+ // Determine the effective key for this pass
1946− /// does, a later condition over an earlier one.
2558+ let effective_key = if state_prefix.is_empty() {
1947− fn of(attrs: &[Attribute], at: &Condition) -> Sizes {
2559+ if is_prefixed_attr(&attr.key) {
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 {
1953 continue;
2560 continue;
1955− if condition.holds_at(at) {
1956− read.push((condition, name, value));
1959− read.sort_by_cached_key(|(condition, _, _)| condition.order());
1960− for (_, name, value) in read {
1963− let size = Size::of(value);
1964− sizes.width = Some(size);
1965− sizes.width_word |= size != Size::Set;
1968− let size = Size::of(value);
1969− sizes.height = Some(size);
1970− sizes.height_word |= size != Size::Set;
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,
1980− }
2562+ attr.key.as_str()
1981− sizes
2563+ } else {
1982− }
2564+ match attr.key.strip_prefix(state_prefix) {
1984− /// The element writes `property` itself: a layout word leaves it alone.
2566+ None => continue,
1985− fn writes(&self, property: &str) -> bool {
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),
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
2003− fn push(&self, css: &mut String, property: &str, value: &str) {
2004− if property == "flex" && !self.flex {
2005− let longhands = match value {
2007− ("flex-grow", "1"),
2008− ("flex-shrink", "1"),
2009− ("flex-basis", "0%"),
2011− // The reset, `0 1 auto`
2013− ("flex-grow", "0"),
2014− ("flex-shrink", "1"),
2015− ("flex-basis", "auto"),
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);
2027− if !self.writes(property) {
2028− push_css(css, property, value);
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),
2049− if let Some(size) = size {
2050− sets.extend_from_slice(sizing(dim, size, Some(axis)));
2052− resets.extend_from_slice(&sizing_properties(dim));
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) {
2060− written.push(property);
2061− sizes.push(&mut css, property, value);
2063− for &(property, value) in &sets {
2064− sizes.push(&mut css, property, value);
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,
2072−fn sizing_changes(attrs: &[Attribute], flow: &Flow) -> Vec<(Vec<usize>, String)> {
2075− .map(|(at, axis)| (at.clone(), sizing_rule(attrs, at, *axis)))
2076− .filter(|(_, body)| !body.is_empty())
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(),
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));
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);
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;",
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);
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)
2143− for (index, attr) in attrs.iter().enumerate() {
2147− let Some(effective_key) = under(&attr.key, condition) else {
2150− if on_children && crate::vocab::places_in_parent(effective_key, attr.value.as_deref()) {
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()) {
2160 let val = attr.value.as_deref();
2570 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()) {
2167 match effective_key {
2572 match effective_key {
2168− // htmlang's own words: they lay out children or place the
2573+ // Layout
2169− // element in its parent, and mean more than one CSS property
2574+ "spacing" | "gap" => {
2170− "spacing" if !lays_out_children => {}
2172 if let Some(v) = val {
2575 if let Some(v) = val {
2173− push_css(&mut css, "gap", &with_px("gap", v));
2576+ push_css(&mut css, "gap", &css_px(v));
2176−
2579+ "padding" => {
2177− // Sizing: `fill` and `shrink` compile against the parent's
2580+ if let Some(v) = val {
2178− // direction. Only the last `width` (`height`) counts, as for
2581+ push_css(&mut css, "padding", &css_px_multi(v));
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| {
2183− && under(&a.key, condition) == Some(effective_key)
2184− && a.value.as_deref().is_some_and(|v| !v.trim().is_empty())
2189− let dim = if effective_key == "width" {
2583+ }
2190− Dim::Width
2584+ "padding-x" => {
2191− } else {
2585+ if let Some(v) = val {
2192− Dim::Height
2586+ // Logical property covers both inline sides in one
2193− };
2587+ // declaration; for symmetric values this is visually
2194− let size = Size::of(val.unwrap_or_default());
2588+ // identical to padding-left/right in LTR and RTL.
2195− // What the element writes itself, which a layout word
2589+ push_css(&mut css, "padding-inline", &css_px(v));
2197− let sizes = Sizes::of(attrs, condition);
2198− for &(property, value) in sizing(dim, size, axis) {
2199− sizes.push(&mut css, property, value);
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`
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",
2218− && name == effective_key
2221− && c.holds_at(condition)
2224− .is_some_and(|v| !v.trim().is_empty() && Size::of(v) != Size::Set)
2227− let dim = if effective_key == "width" {
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);
2238 if let Some(v) = val {
2593 if let Some(v) = val {
2239− push_css(&mut css, effective_key, &with_px(effective_key, v));
2594+ push_css(&mut css, "padding-block", &css_px(v));
2242−
2597+ "padding-top" => {
2243− // Alignment: auto margins, which work along either direction.
2598+ if let Some(v) = val {
2244− // They are written last, so a `margin` on the same element
2599+ push_css(&mut css, "padding-top", &css_px(v));
2245− // keeps its other sides (`center-x, margin 20`)
2600+ }
2246− "center-x" => {
2601+ }
2247− push_css(&mut aligned, "margin-left", "auto");
2602+ "padding-bottom" => {
2248− push_css(&mut aligned, "margin-right", "auto");
2603+ if let Some(v) = val {
2604+ push_css(&mut css, "padding-bottom", &css_px(v));
2250− "center-y" => {
2607+ "padding-left" => {
2251− push_css(&mut aligned, "margin-top", "auto");
2608+ if let Some(v) = val {
2252− push_css(&mut aligned, "margin-bottom", "auto");
2609+ push_css(&mut css, "padding-left", &css_px(v));
2612+ "padding-right" => {
2613+ if let Some(v) = val {
2614+ push_css(&mut css, "padding-right", &css_px(v));
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"),
2259− "wrap" if lays_out_children => push_css(&mut css, "flex-wrap", "wrap"),
2262− // Grid
2618+ // Sizing
2263− "grid-cols" | "grid-rows" if !lays_out_children => {}
2619+ "width" => {
2264− "grid-cols" | "grid-rows" => {
2265 if let Some(v) = val {
2620 if let Some(v) = val {
2266− let property = if effective_key == "grid-cols" {
2621+ match v {
2267− "grid-template-columns"
2622+ "fill" => match parent_kind {
2268− } else {
2623+ Some(ElementKind::Row) => {
2269− "grid-template-rows"
2624+ push_css(&mut css, "flex", "1");
2270− };
2625+ push_css(&mut css, "min-width", "0");
2271− match v.parse::<u32>() {
2626+ }
2272− Ok(n) => push_css(&mut css, property, &format!("repeat({},1fr)", n)),
2627+ _ => push_css(&mut css, "width", "100%"),
2273− Err(_) => push_css(&mut css, property, &with_px(property, v)),
2628+ },
2629+ "shrink" => push_css(&mut css, "flex-shrink", "0"),
2630+ _ => push_css(&mut css, "width", &css_px(v)),
2277− "col-span" | "row-span" => {
2634+ "height" => {
2278 if let Some(v) = val {
2635 if let Some(v) = val {
2279− let property = if effective_key == "col-span" {
2636+ match v {
2280− "grid-column"
2637+ "fill" => match parent_kind {
2281− } else {
2638+ Some(ElementKind::Column) => {
2282− "grid-row"
2639+ push_css(&mut css, "flex", "1");
2283− };
2640+ push_css(&mut css, "min-height", "0");
2284− push_css(&mut css, property, &format!("span {}", v));
2641+ }
2642+ _ => push_css(&mut css, "height", "100%"),
2644+ "shrink" => push_css(&mut css, "flex-shrink", "0"),
2645+ _ => push_css(&mut css, "height", &css_px(v)),
2287−
2649+ "min-width" => {
2288− // CSS's `line-clamp` has no support yet without its
2289− // `-webkit-` fallback, which needs a box to clamp
2291 if let Some(v) = val {
2650 if let Some(v) = val {
2292− push_css(&mut css, "display", "-webkit-box");
2651+ push_css(&mut css, "min-width", &css_px(v));
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");
2298−
2654+ "max-width" => {
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) => {
2305 if let Some(v) = val {
2655 if let Some(v) = val {
2306− push_css(&mut css, key, &with_px(key, v));
2656+ push_css(&mut css, "max-width", &css_px(v));
2660+ if let Some(v) = val {
2661+ push_css(&mut css, "min-height", &css_px(v));
2665+ if let Some(v) = val {
2666+ push_css(&mut css, "max-height", &css_px(v));
2310− _ => {}
2670+ // Alignment
2311− }
2671+ "center-x" => match parent_kind {
2672+ Some(ElementKind::Column) | Some(ElementKind::El) => {
2673+ push_css(&mut css, "align-self", "center");
2676+ push_css(&mut css, "margin-left", "auto");
2677+ push_css(&mut css, "margin-right", "auto");
2680+ "center-y" => match parent_kind {
2681+ Some(ElementKind::Row) => push_css(&mut css, "align-self", "center"),
2683+ push_css(&mut css, "margin-top", "auto");
2684+ push_css(&mut css, "margin-bottom", "auto");
2687+ "align-left" => match parent_kind {
2688+ Some(ElementKind::Column) | Some(ElementKind::El) => {
2689+ push_css(&mut css, "align-self", "flex-start");
2691+ _ => push_css(&mut css, "margin-right", "auto"),
2693+ "align-right" => match parent_kind {
2694+ Some(ElementKind::Column) | Some(ElementKind::El) => {
2695+ push_css(&mut css, "align-self", "flex-end");
2697+ _ => push_css(&mut css, "margin-left", "auto"),
2699+ "align-top" => match parent_kind {
2700+ Some(ElementKind::Row) => push_css(&mut css, "align-self", "flex-start"),
2701+ _ => push_css(&mut css, "margin-bottom", "auto"),
2703+ "align-bottom" => match parent_kind {
2704+ Some(ElementKind::Row) => push_css(&mut css, "align-self", "flex-end"),
2705+ _ => push_css(&mut css, "margin-top", "auto"),
2710+ if let Some(v) = val {
2711+ push_css(&mut css, "background", v);
2715+ if let Some(v) = val {
2716+ push_css(&mut css, "color", v);
2720+ if let Some(v) = val {
2721+ let parts: Vec<&str> = v.splitn(2, ' ').collect();
2722+ if parts.len() == 2 {
2726+ &format!("{} solid {}", css_px(parts[0]), parts[1]),
2732+ &format!("{} solid currentColor", css_px(parts[0])),
2737+ "border-top" | "border-bottom" | "border-left" | "border-right" => {
2738+ if let Some(v) = val {
2739+ let parts: Vec<&str> = v.splitn(2, ' ').collect();
2740+ if parts.len() == 2 {
2744+ &format!("{} solid {}", css_px(parts[0]), parts[1]),
2750+ &format!("{} solid currentColor", css_px(parts[0])),
2756+ if let Some(v) = val {
2757+ push_css(&mut css, "border-radius", &css_px(v));
2760+ "bold" => push_css(&mut css, "font-weight", "bold"),
2761+ "italic" => push_css(&mut css, "font-style", "italic"),
2762+ "underline" => push_css(&mut css, "text-decoration", "underline"),
2764+ if let Some(v) = val {
2765+ push_css(&mut css, "font-size", &css_px(v));
2769+ if let Some(v) = val {
2770+ // `font "Inter, sans-serif"` quotes a whole font stack so
2771+ // its commas don't split the attribute list.
2772+ let v = match v.strip_prefix('"').and_then(|v| v.strip_suffix('"')) {
2773+ Some(stack) if stack.contains(',') => stack,
2776+ push_css(&mut css, "font-family", v);
2780+ if let Some(v) = val {
2781+ push_css(&mut css, "transition", v);
2785+ if let Some(v) = val {
2786+ push_css(&mut css, "cursor", v);
2790+ if let Some(v) = val {
2791+ push_css(&mut css, "opacity", v);
2797+ if let Some(v) = val {
2798+ push_css(&mut css, "text-align", v);
2802+ if let Some(v) = val {
2803+ push_css(&mut css, "line-height", &css_line_height(v));
2806+ "letter-spacing" => {
2807+ if let Some(v) = val {
2808+ push_css(&mut css, "letter-spacing", &css_px(v));
2811+ "text-transform" => {
2812+ if let Some(v) = val {
2813+ push_css(&mut css, "text-transform", v);
2817+ if let Some(v) = val {
2818+ push_css(&mut css, "white-space", v);
2822+ // Overflow & positioning
2824+ if let Some(v) = val {
2825+ push_css(&mut css, "overflow", v);
2829+ if let Some(v) = val {
2830+ push_css(&mut css, "position", v);
2834+ if let Some(v) = val {
2835+ push_css(&mut css, "top", &css_px(v));
2839+ if let Some(v) = val {
2840+ push_css(&mut css, "right", &css_px(v));
2844+ if let Some(v) = val {
2845+ push_css(&mut css, "bottom", &css_px(v));
2849+ if let Some(v) = val {
2850+ push_css(&mut css, "left", &css_px(v));
2854+ if let Some(v) = val {
2855+ push_css(&mut css, "z-index", v);
2859+ // Display & visibility
2861+ if let Some(v) = val {
2862+ push_css(&mut css, "display", v);
2866+ if let Some(v) = val {
2867+ push_css(&mut css, "visibility", v);
2870+ "hidden" => push_css(&mut css, "display", "none"),
2872+ // Transform & filters
2874+ if let Some(v) = val {
2875+ push_css(&mut css, "transform", v);
2878+ "backdrop-filter" => {
2879+ if let Some(v) = val {
2880+ push_css(&mut css, "backdrop-filter", v);
2886+ if let Some(v) = val {
2887+ push_css(&mut css, "box-shadow", v);
2892+ "wrap" => push_css(&mut css, "flex-wrap", "wrap"),
2894+ if let Some(v) = val {
2895+ push_css(&mut css, "column-gap", &css_px(v));
2899+ if let Some(v) = val {
2900+ push_css(&mut css, "row-gap", &css_px(v));
2906+ push_css(&mut css, "display", "grid");
2909+ if let Some(v) = val {
2910+ if let Ok(n) = v.parse::<u32>() {
2913+ "grid-template-columns",
2914+ &format!("repeat({},1fr)", n),
2917+ push_css(&mut css, "grid-template-columns", v);
2922+ if let Some(v) = val {
2923+ if let Ok(n) = v.parse::<u32>() {
2926+ "grid-template-rows",
2927+ &format!("repeat({},1fr)", n),
2930+ push_css(&mut css, "grid-template-rows", v);
2935+ if let Some(v) = val {
2936+ push_css(&mut css, "grid-column", &format!("span {}", v));
2940+ if let Some(v) = val {
2941+ push_css(&mut css, "grid-row", &format!("span {}", v));
2947+ if let Some(v) = val {
2948+ push_css(&mut css, "animation", v);
2953+ "aspect-ratio" => {
2954+ if let Some(v) = val {
2955+ push_css(&mut css, "aspect-ratio", v);
2959+ // CSS containment for rendering performance
2961+ if let Some(v) = val {
2962+ push_css(&mut css, "contain", v);
2964+ push_css(&mut css, "contain", "layout style paint");
2967+ "content-visibility" => {
2968+ if let Some(v) = val {
2969+ push_css(&mut css, "content-visibility", v);
2971+ push_css(&mut css, "content-visibility", "auto");
2975+ // Outline (like border but doesn't affect layout)
2977+ if let Some(v) = val {
2978+ let parts: Vec<&str> = v.splitn(2, ' ').collect();
2979+ if parts.len() == 2 {
2983+ &format!("{} solid {}", css_px(parts[0]), parts[1]),
2989+ &format!("{} solid currentColor", css_px(parts[0])),
2995+ // Logical properties (i18n-aware)
2996+ "padding-inline" => {
2997+ if let Some(v) = val {
2998+ push_css(&mut css, "padding-inline", &css_px_multi(v));
3001+ "padding-block" => {
3002+ if let Some(v) = val {
3003+ push_css(&mut css, "padding-block", &css_px_multi(v));
3006+ "margin-inline" => {
3007+ if let Some(v) = val {
3008+ push_css(&mut css, "margin-inline", &css_px_multi(v));
3011+ "margin-block" => {
3012+ if let Some(v) = val {
3013+ push_css(&mut css, "margin-block", &css_px_multi(v));
3017+ // Logical property start/end variants
3018+ "padding-inline-start"
3019+ | "padding-inline-end"
3020+ | "padding-block-start"
3021+ | "padding-block-end"
3022+ | "margin-inline-start"
3023+ | "margin-inline-end"
3024+ | "margin-block-start"
3025+ | "margin-block-end" => {
3026+ if let Some(v) = val {
3027+ push_css(&mut css, effective_key, &css_px(v));
3032+ "inset-inline" | "inset-block" => {
3033+ if let Some(v) = val {
3034+ push_css(&mut css, effective_key, &css_px_multi(v));
3037+ "inset-inline-start" | "inset-inline-end" | "inset-block-start" | "inset-block-end" => {
3038+ if let Some(v) = val {
3039+ push_css(&mut css, effective_key, &css_px(v));
3046+ | "border-inline-start"
3047+ | "border-inline-end"
3048+ | "border-block-start"
3049+ | "border-block-end" => {
3050+ if let Some(v) = val {
3051+ push_css(&mut css, effective_key, v);
3055+ // Logical border-radius
3056+ "border-start-start-radius"
3057+ | "border-start-end-radius"
3058+ | "border-end-start-radius"
3059+ | "border-end-end-radius" => {
3060+ if let Some(v) = val {
3061+ push_css(&mut css, effective_key, &css_px(v));
3065+ // Logical scroll margins & padding
3066+ "scroll-margin-inline"
3067+ | "scroll-margin-block"
3068+ | "scroll-padding-inline"
3069+ | "scroll-padding-block" => {
3070+ if let Some(v) = val {
3071+ push_css(&mut css, effective_key, &css_px_multi(v));
3076+ "inline-size" | "block-size" | "min-inline-size" | "max-inline-size"
3077+ | "min-block-size" | "max-block-size" => {
3078+ if let Some(v) = val {
3079+ push_css(&mut css, effective_key, &css_px(v));
3084+ "scroll-snap-type" => {
3085+ if let Some(v) = val {
3086+ push_css(&mut css, "scroll-snap-type", v);
3089+ "scroll-snap-align" => {
3090+ if let Some(v) = val {
3091+ push_css(&mut css, "scroll-snap-align", v);
3097+ if let Some(v) = val {
3098+ push_css(&mut css, "margin", &css_px_multi(v));
3102+ if let Some(v) = val {
3103+ push_css(&mut css, "margin-inline", &css_px(v));
3107+ if let Some(v) = val {
3108+ push_css(&mut css, "margin-block", &css_px(v));
3114+ if let Some(v) = val {
3115+ push_css(&mut css, "filter", v);
3119+ // Object fit/position (for images)
3121+ if let Some(v) = val {
3122+ push_css(&mut css, "object-fit", v);
3125+ "object-position" => {
3126+ if let Some(v) = val {
3127+ push_css(&mut css, "object-position", v);
3133+ if let Some(v) = val {
3134+ push_css(&mut css, "text-shadow", v);
3139+ "text-overflow" => {
3140+ if let Some(v) = val {
3141+ push_css(&mut css, "text-overflow", v);
3146+ "pointer-events" => {
3147+ if let Some(v) = val {
3148+ push_css(&mut css, "pointer-events", v);
3152+ if let Some(v) = val {
3153+ push_css(&mut css, "user-select", v);
3157+ // Flexbox/grid alignment
3158+ "justify-content" => {
3159+ if let Some(v) = val {
3160+ push_css(&mut css, "justify-content", v);
3164+ if let Some(v) = val {
3165+ push_css(&mut css, "align-items", v);
3171+ if let Some(v) = val {
3172+ push_css(&mut css, "order", v);
3176+ // Background extras
3177+ "background-size" => {
3178+ if let Some(v) = val {
3179+ push_css(&mut css, "background-size", v);
3182+ "background-position" => {
3183+ if let Some(v) = val {
3184+ push_css(&mut css, "background-position", v);
3187+ "background-repeat" => {
3188+ if let Some(v) = val {
3189+ push_css(&mut css, "background-repeat", v);
3195+ if let Some(v) = val {
3196+ push_css(&mut css, "word-break", v);
3199+ "overflow-wrap" => {
3200+ if let Some(v) = val {
3201+ push_css(&mut css, "overflow-wrap", v);
3205+ // Container queries
3207+ push_css(&mut css, "container-type", "inline-size");
3209+ "container-name" => {
3210+ if let Some(v) = val {
3211+ push_css(&mut css, "container-name", v);
3214+ "container-type" => {
3215+ if let Some(v) = val {
3216+ push_css(&mut css, "container-type", v);
3222+ if let Some(v) = val {
3223+ push_css(&mut css, "overflow-x", v);
3227+ if let Some(v) = val {
3228+ push_css(&mut css, "overflow-y", v);
3232+ // Inset (shorthand for top/right/bottom/left)
3234+ if let Some(v) = val {
3235+ push_css(&mut css, "inset", &css_px(v));
3239+ // Accent & caret colors
3240+ "accent-color" => {
3241+ if let Some(v) = val {
3242+ push_css(&mut css, "accent-color", v);
3246+ if let Some(v) = val {
3247+ push_css(&mut css, "caret-color", v);
3251+ // Color scheme & appearance
3252+ "color-scheme" => {
3253+ if let Some(v) = val {
3254+ push_css(&mut css, "color-scheme", v);
3258+ if let Some(v) = val {
3259+ push_css(&mut css, "appearance", v);
3265+ if let Some(v) = val {
3266+ push_css(&mut css, "list-style", v);
3271+ "border-collapse" => {
3272+ if let Some(v) = val {
3273+ push_css(&mut css, "border-collapse", v);
3276+ "border-spacing" => {
3277+ if let Some(v) = val {
3278+ push_css(&mut css, "border-spacing", &css_px(v));
3283+ "text-decoration" => {
3284+ if let Some(v) = val {
3285+ push_css(&mut css, "text-decoration", v);
3288+ "text-decoration-color" => {
3289+ if let Some(v) = val {
3290+ push_css(&mut css, "text-decoration-color", v);
3293+ "text-decoration-thickness" => {
3294+ if let Some(v) = val {
3295+ push_css(&mut css, "text-decoration-thickness", &css_px(v));
3298+ "text-decoration-style" => {
3299+ if let Some(v) = val {
3300+ push_css(&mut css, "text-decoration-style", v);
3303+ "text-underline-offset" => {
3304+ if let Some(v) = val {
3305+ push_css(&mut css, "text-underline-offset", &css_px(v));
3310+ "column-width" => {
3311+ if let Some(v) = val {
3312+ push_css(&mut css, "column-width", &css_px(v));
3316+ if let Some(v) = val {
3317+ push_css(&mut css, "column-rule", v);
3321+ // Place items/self
3323+ if let Some(v) = val {
3324+ push_css(&mut css, "place-items", v);
3328+ if let Some(v) = val {
3329+ push_css(&mut css, "place-self", v);
3334+ "scroll-behavior" => {
3335+ if let Some(v) = val {
3336+ push_css(&mut css, "scroll-behavior", v);
3342+ if let Some(v) = val {
3343+ push_css(&mut css, "resize", v);
3347+ // New CSS properties
3349+ if let Some(v) = val {
3350+ push_css(&mut css, "clip-path", v);
3353+ "mix-blend-mode" => {
3354+ if let Some(v) = val {
3355+ push_css(&mut css, "mix-blend-mode", v);
3358+ "background-blend-mode" => {
3359+ if let Some(v) = val {
3360+ push_css(&mut css, "background-blend-mode", v);
3363+ "writing-mode" => {
3364+ if let Some(v) = val {
3365+ push_css(&mut css, "writing-mode", v);
3368+ "column-count" => {
3369+ if let Some(v) = val {
3370+ push_css(&mut css, "column-count", v);
3374+ if let Some(v) = val {
3375+ push_css(&mut css, "column-gap", &css_px(v));
3379+ if let Some(v) = val {
3380+ push_css(&mut css, "text-indent", &css_px(v));
3384+ if let Some(v) = val {
3385+ push_css(&mut css, "hyphens", v);
3389+ if let Some(v) = val {
3390+ push_css(&mut css, "flex-grow", v);
3394+ if let Some(v) = val {
3395+ push_css(&mut css, "flex-shrink", v);
3399+ if let Some(v) = val {
3400+ push_css(&mut css, "flex-basis", &css_px(v));
3404+ if let Some(v) = val {
3405+ push_css(&mut css, "isolation", v);
3408+ "place-content" => {
3409+ if let Some(v) = val {
3410+ push_css(&mut css, "place-content", v);
3413+ "background-image" => {
3414+ if let Some(v) = val {
3415+ push_css(&mut css, "background-image", v);
3419+ if let Some(v) = val {
3420+ push_css(&mut css, "font-weight", v);
3424+ if let Some(v) = val {
3425+ push_css(&mut css, "font-style", v);
3429+ if let Some(v) = val {
3430+ push_css(&mut css, "text-wrap", v);
3434+ if let Some(v) = val {
3435+ push_css(&mut css, "will-change", v);
3438+ "touch-action" => {
3439+ if let Some(v) = val {
3440+ push_css(&mut css, "touch-action", v);
3443+ "vertical-align" => {
3444+ if let Some(v) = val {
3445+ push_css(&mut css, "vertical-align", v);
3448+ "scroll-margin" => {
3449+ if let Some(v) = val {
3450+ push_css(&mut css, "scroll-margin", &css_px(v));
3453+ "scroll-margin-top"
3454+ | "scroll-margin-bottom"
3455+ | "scroll-margin-left"
3456+ | "scroll-margin-right" => {
3457+ if let Some(v) = val {
3458+ push_css(&mut css, effective_key, &css_px(v));
3461+ "scroll-padding" => {
3462+ if let Some(v) = val {
3463+ push_css(&mut css, "scroll-padding", &css_px(v));
3466+ "scroll-padding-top"
3467+ | "scroll-padding-bottom"
3468+ | "scroll-padding-left"
3469+ | "scroll-padding-right" => {
3470+ if let Some(v) = val {
3471+ push_css(&mut css, effective_key, &css_px(v));
3475+ if let Some(v) = val {
3476+ push_css(&mut css, "direction", v);
3481+ if let Some(v) = val {
3482+ // Wrap in quotes if not already quoted and not a CSS keyword
3483+ if v.starts_with('"')
3484+ || v.starts_with('\'')
3487+ || v.starts_with("attr(")
3488+ || v.starts_with("counter(")
3490+ push_css(&mut css, "content", v);
3492+ push_css(&mut css, "content", &format!("\"{}\"", v));
3497+ // --- CSS Shorthands ---
3499+ push_css(&mut css, "overflow", "hidden");
3500+ push_css(&mut css, "text-overflow", "ellipsis");
3501+ push_css(&mut css, "white-space", "nowrap");
3504+ if let Some(v) = val {
3505+ push_css(&mut css, "display", "-webkit-box");
3506+ push_css(&mut css, "-webkit-line-clamp", v);
3507+ push_css(&mut css, "-webkit-box-orient", "vertical");
3508+ push_css(&mut css, "overflow", "hidden");
3512+ if let Some(v) = val {
3513+ push_css(&mut css, "filter", &format!("blur({})", css_px(v)));
3516+ "backdrop-blur" => {
3517+ if let Some(v) = val {
3518+ push_css(&mut css, "backdrop-filter", &format!("blur({})", css_px(v)));
3521+ "no-scrollbar" => {
3522+ push_css(&mut css, "scrollbar-width", "none");
3523+ push_css(&mut css, "-ms-overflow-style", "none");
3529+ "linear-gradient(90deg,#e5e7eb 25%,#f3f4f6 50%,#e5e7eb 75%)",
3531+ push_css(&mut css, "background-size", "200% 100%");
3535+ "hl-skeleton 1.5s ease-in-out infinite",
3539+ if let Some(v) = val {
3540+ // Parse: "from to [angle]" or "color1 color2 [angle]"
3541+ let parts: Vec<&str> = v.split_whitespace().collect();
3542+ let bg = if parts.len() >= 3
3543+ && (parts[2].ends_with("deg")
3544+ || parts[2].ends_with("turn")
3545+ || parts[2].ends_with("rad"))
3547+ format!("linear-gradient({},{},{})", parts[2], parts[0], parts[1])
3548+ } else if parts.len() >= 2 {
3549+ format!("linear-gradient({},{})", parts[0], parts[1])
3551+ format!("linear-gradient({},transparent)", parts[0])
3553+ push_css(&mut css, "background", &bg);
3558+ "grid-template-areas" => {
3559+ if let Some(v) = val {
3560+ push_css(&mut css, "grid-template-areas", v);
3564+ if let Some(v) = val {
3565+ push_css(&mut css, "grid-area", v);
3569+ // View transitions
3570+ "view-transition-name" => {
3571+ if let Some(v) = val {
3572+ push_css(&mut css, "view-transition-name", v);
3578+ "grid-template-columns" => {
3579+ if let Some(v) = val {
3580+ push_css(&mut css, "grid-template-columns", v);
3583+ "grid-template-rows" => {
3584+ if let Some(v) = val {
3585+ push_css(&mut css, "grid-template-rows", v);
3589+ // Scroll-driven animations
3590+ "animation-timeline" => {
3591+ if let Some(v) = val {
3592+ push_css(&mut css, "animation-timeline", v);
3595+ "animation-range" => {
3596+ if let Some(v) = val {
3597+ push_css(&mut css, "animation-range", v);
3600+ "view-timeline-name" => {
3601+ if let Some(v) = val {
3602+ push_css(&mut css, "view-timeline-name", v);
3605+ "view-timeline-axis" => {
3606+ if let Some(v) = val {
3607+ push_css(&mut css, "view-timeline-axis", v);
3610+ "scroll-timeline-name" => {
3611+ if let Some(v) = val {
3612+ push_css(&mut css, "scroll-timeline-name", v);
3615+ "scroll-timeline-axis" => {
3616+ if let Some(v) = val {
3617+ push_css(&mut css, "scroll-timeline-axis", v);
3621+ // Anchor positioning
3623+ if let Some(v) = val {
3624+ push_css(&mut css, "anchor-name", v);
3627+ "position-anchor" => {
3628+ if let Some(v) = val {
3629+ push_css(&mut css, "position-anchor", v);
3632+ "position-area" => {
3633+ if let Some(v) = val {
3634+ push_css(&mut css, "position-area", v);
3638+ // initial-letter (drop caps)
3639+ "initial-letter" => {
3640+ if let Some(v) = val {
3641+ push_css(&mut css, "initial-letter", v);
3645+ // Critical CSS hint — not CSS, handled elsewhere
3648+ // Identity and HTML passthrough — not CSS
3649+ "id" | "class" => {}
3650+ "type" | "placeholder" | "name" | "value" | "disabled" | "required" | "checked"
3651+ | "for" | "action" | "method" | "autocomplete" | "min" | "max" | "step" | "pattern"
3652+ | "maxlength" | "rows" | "cols" | "multiple" | "alt" | "role" | "tabindex"
3653+ | "title" | "controls" | "autoplay" | "loop" | "muted" | "playsinline" | "poster"
3654+ | "preload" | "loading" | "decoding" | "ordered" | "src" | "open" | "novalidate"
3655+ | "low" | "high" | "optimum" | "colspan" | "rowspan" | "scope" | "inline"
3656+ | "responsive" | "datetime" | "media" | "sizes" | "srcset" | "cite" | "list"
3657+ | "sandbox" | "allow" | "allowfullscreen" | "referrerpolicy" | "formaction"
3658+ | "formmethod" | "formtarget" | "target" | "autofocus" => {}
2314− css.push_str(&aligned);
@@ -2322,10 +3671,262 @@ fn push_css(css: &mut String, prop: &str, value: &str) {
2322 css.push(';');
3671 css.push(';');
3674+/// Known CSS units — if a value ends with one, skip appending `px`.
3675+/// Format a length value: a bare number gets `px` appended; anything else
3676+/// (values with units, keywords like `auto`, functions like `calc(...)`) is
3677+/// passed through unchanged.
3678+fn css_px(value: &str) -> String {
3679+ let v = value.trim();
3681+ return "0".to_string();
3683+ let is_bare_number = !v.is_empty()
3684+ && v.bytes().all(|b| b.is_ascii_digit() || matches!(b, b'.' | b'-' | b'+'))
3685+ && v.parse::<f64>().is_ok();
3686+ if is_bare_number {
3693+/// Rewrite literal values that match a declared CSS custom property (from
3694+/// `@theme` or `@let --name value`) to `var(--name)` references. Matches are
3695+/// anchored to CSS value boundaries so e.g. `#3b82f6` inside a longer hex or
3696+/// inside an identifier is not replaced. The `:root` block is emitted before
3697+/// this call runs, so its declarations are not affected.
3698+fn substitute_css_vars(css: &str, vars: &[(String, String)]) -> String {
3699+ if css.is_empty() || vars.is_empty() {
3700+ return css.to_string();
3702+ // Prefer longer values first so that if two vars share a prefix, the
3703+ // longer (more specific) match wins.
3704+ let mut pairs: Vec<(&str, String)> = vars
3706+ .filter(|(name, value)| name.starts_with("--") && !value.is_empty())
3707+ .map(|(name, value)| (value.as_str(), format!("var({})", name)))
3709+ pairs.sort_by_key(|(v, _)| std::cmp::Reverse(v.len()));
3710+ if pairs.is_empty() {
3711+ return css.to_string();
3714+ let is_boundary_before = |b: Option<u8>| match b {
3716+ Some(c) => matches!(c, b':' | b' ' | b',' | b'(' | b';' | b'{' | b'\n' | b'\t'),
3718+ let is_boundary_after = |b: Option<u8>| match b {
3720+ Some(c) => matches!(c, b';' | b'}' | b',' | b' ' | b')' | b'\n' | b'\t'),
3723+ let bytes = css.as_bytes();
3724+ let mut out = String::with_capacity(css.len());
3726+ let mut prev: Option<u8> = None;
3727+ // Only declaration values are rewritten — never selectors or at-rule
3728+ // preludes such as `@media (min-width:768px)`. `blocks` records, for
3729+ // each open `{`, whether it holds declarations (a style rule) or nested
3730+ // rules (an at-rule like `@media` / `@layer`).
3731+ let mut blocks: Vec<bool> = Vec::new();
3732+ let mut prelude_start = 0;
3733+ let mut in_value = false;
3734+ while i < bytes.len() {
3737+ let prelude = css[prelude_start..i].trim_start();
3738+ blocks.push(!prelude.starts_with('@'));
3740+ prelude_start = i + 1;
3745+ prelude_start = i + 1;
3749+ prelude_start = i + 1;
3751+ b':' if blocks.last() == Some(&true) => in_value = true,
3754+ if in_value && is_boundary_before(prev) {
3755+ let mut matched = false;
3756+ for (val, repl) in &pairs {
3757+ let vb = val.as_bytes();
3758+ if i + vb.len() <= bytes.len() && &bytes[i..i + vb.len()] == vb {
3759+ let next = bytes.get(i + vb.len()).copied();
3760+ if is_boundary_after(next) {
3761+ out.push_str(repl);
3762+ prev = repl.as_bytes().last().copied();
3773+ // Advance by one UTF-8 code point.
3776+ while i < bytes.len() && (bytes[i] & 0xC0) == 0x80 {
3779+ out.push_str(&css[start..i]);
3780+ prev = bytes.get(i - 1).copied();
3785+/// Scan generated CSS for literal property values that repeat often enough
3786+/// that substituting them with an auto-named custom property would reduce
3787+/// total byte count. Returns the rewritten CSS and any new vars that should
3788+/// be appended to `:root`.
3790+/// The algorithm only promotes a value if it strictly saves bytes after
3791+/// accounting for the `--xN:value;` declaration overhead plus the
3792+/// `var(--xN)` reference cost at each call site. Values that are already
3793+/// `var(...)` references or contain `var(` calls are skipped so we never
3794+/// nest references. Names avoid collisions with `existing_vars`.
3795+fn auto_extract_repeats(
3797+ existing_vars: &[(String, String)],
3798+) -> (String, Vec<(String, String)>) {
3799+ if css.is_empty() {
3800+ return (css.to_string(), Vec::new());
3802+ // Count occurrences of each distinct property value (the text between
3803+ // `:` and the next `;` or `}` at the top level of a declaration block,
3804+ // ignoring balanced parentheses so that e.g. `rgba(...)` stays intact).
3805+ let bytes = css.as_bytes();
3806+ let mut counts: HashMap<String, usize> = HashMap::new();
3807+ let mut depth: i32 = 0;
3809+ while i < bytes.len() {
3825+ if depth > 0 && bytes[i] == b':' {
3826+ // Skip past `:` then walk to the terminator.
3828+ let mut end = start;
3829+ let mut pdepth = 0i32;
3830+ while end < bytes.len() {
3832+ b'(' => pdepth += 1,
3833+ b')' if pdepth > 0 => pdepth -= 1,
3834+ b';' | b'}' if pdepth == 0 => break,
3835+ b'{' if pdepth == 0 => break,
3840+ let val = css[start..end].trim();
3841+ if !val.is_empty() && !val.starts_with("var(") && !val.contains("var(") {
3842+ *counts.entry(val.to_string()).or_default() += 1;
3850+ // Decide which values are worth extracting. A value of length L appearing
3851+ // N times costs N*L bytes inline; promoting it costs (L + 6) for the
3852+ // `--hK:V;` declaration plus N * ref_len for the call sites. We estimate
3853+ // ref_len optimistically as `var(--h0)` (9 bytes) and fall back to 10 for
3854+ // two-digit indices, which only affects very large extraction counts.
3855+ let existing: std::collections::HashSet<&str> =
3856+ existing_vars.iter().map(|(n, _)| n.as_str()).collect();
3857+ let mut candidates: Vec<(String, usize)> =
3858+ counts.into_iter().filter(|(_, n)| *n >= 2).collect();
3859+ // Stable, deterministic ordering — longest values first, tiebreak by text.
3860+ candidates.sort_by(|a, b| b.0.len().cmp(&a.0.len()).then_with(|| a.0.cmp(&b.0)));
3862+ let mut extracted: Vec<(String, String)> = Vec::new();
3863+ let mut next_idx: usize = 0;
3864+ for (value, n) in candidates {
3865+ let l = value.len();
3866+ // Allocate the next unused `--hN` name.
3867+ let (name, ref_len) = loop {
3868+ let candidate = format!("--h{}", next_idx);
3870+ let rl = candidate.len() + 6; // `var(` + name + `)`
3871+ if !existing.contains(candidate.as_str())
3872+ && !extracted.iter().any(|(n, _)| *n == candidate)
3874+ break (candidate, rl);
3877+ // Skip if promotion would not strictly reduce byte count.
3878+ // Before: n * l bytes. After: (l + name.len() + 2) for the :root
3879+ // declaration (`<name>:<value>;`) plus n * ref_len for the sites.
3880+ let decl_overhead = l + name.len() + 2;
3881+ let before = n * l;
3882+ let after = decl_overhead + n * ref_len;
3883+ if after < before {
3884+ extracted.push((name, value));
3886+ // Rewind the index so the next value can reuse this slot.
3891+ if extracted.is_empty() {
3892+ return (css.to_string(), Vec::new());
3894+ let new_css = substitute_css_vars(css, &extracted);
3895+ (new_css, extracted)
3898+/// Format a `line-height` value. CSS accepts either a unitless multiplier
3899+/// (e.g. `1.5`) or a length (e.g. `24px`). Plain integers in htmlang source
3900+/// are ambiguous: `[line-height 24]` was historically emitted as `24` (which
3901+/// CSS interprets as 24× font-size — almost never what anyone wants). Treat
3902+/// integers ≥ 2 as pixel lengths; anything with a decimal, an existing unit,
3903+/// or the value `0`/`1` passes through unchanged.
3904+fn css_line_height(value: &str) -> String {
3905+ let v = value.trim();
3906+ if v == "0" || v == "1" {
3907+ return v.to_string();
3909+ // Plain integer — treat as pixel length. Decimals, units, keywords and
3910+ // functions pass through.
3911+ if !v.is_empty() && v.chars().all(|c| c.is_ascii_digit()) {
3912+ return format!("{}px", v);
3917+/// Format multiple space-separated values, each getting px if needed.
3918+fn css_px_multi(value: &str) -> String {
3920+ .split_whitespace()
3922+ .collect::<Vec<_>>()
2325fn extract_id_class(attrs: &[Attribute]) -> (Option<String>, Option<String>) {
3926fn extract_id_class(attrs: &[Attribute]) -> (Option<String>, Option<String>) {
2326 let mut id = None;
3927 let mut id = None;
2327 let mut class = None;
3928 let mut class = None;
2328− for attr in attrs.iter().filter(|a| a.html) {
3929+ for attr in attrs {
2329 match attr.key.as_str() {
3930 match attr.key.as_str() {
2330 "id" => id = attr.value.clone(),
3931 "id" => id = attr.value.clone(),
2331 "class" => class = attr.value.clone(),
3932 "class" => class = attr.value.clone(),
@@ -2335,6 +3936,153 @@ fn extract_id_class(attrs: &[Attribute]) -> (Option<String>, Option<String>) {
2335 (id, class)
3936 (id, class)
3939+/// Read image dimensions from a local file by parsing the header bytes.
3940+/// Supports PNG, JPEG, GIF, WebP, AVIF, and SVG.
3941+fn read_image_dimensions(path: &str) -> Option<(u32, u32)> {
3942+ // SVG: parse as text for viewBox/width/height attributes
3943+ if path.ends_with(".svg") || path.ends_with(".SVG") {
3944+ let text = std::fs::read_to_string(path).ok()?;
3945+ return read_svg_dimensions(&text);
3948+ let data = std::fs::read(path).ok()?;
3949+ if data.len() < 12 {
3953+ // PNG: 8-byte signature, then IHDR chunk with width/height at bytes 16-23
3954+ if data.len() >= 24 && data.starts_with(b"\x89PNG\r\n\x1a\n") {
3955+ let w = u32::from_be_bytes([data[16], data[17], data[18], data[19]]);
3956+ let h = u32::from_be_bytes([data[20], data[21], data[22], data[23]]);
3957+ return Some((w, h));
3960+ // GIF: "GIF87a" or "GIF89a", width/height at bytes 6-9 (little-endian)
3961+ if data.starts_with(b"GIF87a") || data.starts_with(b"GIF89a") {
3962+ let w = u16::from_le_bytes([data[6], data[7]]) as u32;
3963+ let h = u16::from_le_bytes([data[8], data[9]]) as u32;
3964+ return Some((w, h));
3967+ // JPEG: scan for SOF0/SOF2 marker (0xFF 0xC0 or 0xFF 0xC2)
3968+ if data.starts_with(b"\xff\xd8") {
3970+ while i + 9 < data.len() {
3971+ if data[i] != 0xFF {
3975+ let marker = data[i + 1];
3976+ if marker == 0xC0 || marker == 0xC2 {
3977+ let h = u16::from_be_bytes([data[i + 5], data[i + 6]]) as u32;
3978+ let w = u16::from_be_bytes([data[i + 7], data[i + 8]]) as u32;
3979+ return Some((w, h));
3981+ if i + 3 < data.len() {
3982+ let len = u16::from_be_bytes([data[i + 2], data[i + 3]]) as usize;
3990+ // WebP: "RIFF" ... "WEBP", VP8 header at byte 20
3991+ if data.len() >= 30 && &data[..4] == b"RIFF" && &data[8..12] == b"WEBP" {
3992+ if &data[12..16] == b"VP8 " && data.len() >= 30 {
3993+ let w = u16::from_le_bytes([data[26], data[27]]) as u32 & 0x3FFF;
3994+ let h = u16::from_le_bytes([data[28], data[29]]) as u32 & 0x3FFF;
3995+ return Some((w, h));
3997+ if &data[12..16] == b"VP8L" && data.len() >= 25 && data[21] == 0x2F {
3998+ let bits = u32::from_le_bytes([data[22], data[23], data[24], data[25]]);
3999+ let w = (bits & 0x3FFF) + 1;
4000+ let h = ((bits >> 14) & 0x3FFF) + 1;
4001+ return Some((w, h));
4005+ // AVIF: ISOBMFF container with "ftyp" box containing "avif"/"avis" brand,
4006+ // then "ispe" box with width/height
4007+ if data.len() >= 12 && &data[4..8] == b"ftyp" {
4008+ let brand = &data[8..12];
4009+ if brand == b"avif" || brand == b"avis" || brand == b"mif1" {
4010+ return read_avif_dimensions(&data);
4017+/// Parse SVG viewBox or width/height attributes to get dimensions.
4018+fn read_svg_dimensions(text: &str) -> Option<(u32, u32)> {
4019+ // Try viewBox first: viewBox="minX minY width height"
4020+ if let Some(vb_start) = text.find("viewBox=\"") {
4021+ let rest = &text[vb_start + 9..];
4022+ if let Some(end) = rest.find('"') {
4023+ let parts: Vec<&str> = rest[..end].split_whitespace().collect();
4024+ if parts.len() == 4
4025+ && let (Ok(w), Ok(h)) = (parts[2].parse::<f64>(), parts[3].parse::<f64>())
4029+ return Some((w.round() as u32, h.round() as u32));
4033+ // Fall back to width/height attributes on <svg>
4034+ let svg_tag = text.find("<svg")?;
4035+ let tag_end = text[svg_tag..].find('>')? + svg_tag;
4036+ let tag = &text[svg_tag..tag_end];
4037+ let w = extract_svg_attr(tag, "width")?;
4038+ let h = extract_svg_attr(tag, "height")?;
4042+fn extract_svg_attr(tag: &str, attr: &str) -> Option<u32> {
4043+ let needle = format!("{}=\"", attr);
4044+ let start = tag.find(&needle)? + needle.len();
4045+ let rest = &tag[start..];
4046+ let end = rest.find('"')?;
4047+ let val = rest[..end].trim_end_matches("px");
4048+ val.parse::<f64>().ok().map(|v| v.round() as u32)
4051+/// Parse AVIF (ISOBMFF) container to find ispe box with image dimensions.
4052+fn read_avif_dimensions(data: &[u8]) -> Option<(u32, u32)> {
4053+ // Walk ISOBMFF boxes looking for "ispe" (image spatial extents)
4055+ while i + 8 <= data.len() {
4057+ u32::from_be_bytes([data[i], data[i + 1], data[i + 2], data[i + 3]]) as usize;
4058+ let box_type = &data[i + 4..i + 8];
4062+ let box_end = (i + box_size).min(data.len());
4063+ // ispe box: 4 bytes version/flags + 4 bytes width + 4 bytes height
4064+ if box_type == b"ispe" && box_end >= i + 20 {
4065+ let w = u32::from_be_bytes([data[i + 12], data[i + 13], data[i + 14], data[i + 15]]);
4066+ let h = u32::from_be_bytes([data[i + 16], data[i + 17], data[i + 18], data[i + 19]]);
4067+ return Some((w, h));
4069+ // Recurse into container boxes (meta, iprp, ipco)
4072+ b"meta" | b"iprp" | b"ipco" | b"moov" | b"trak" | b"mdia"
4074+ let header_size = if box_type == b"meta" { 12 } else { 8 };
4075+ if i + header_size < box_end
4076+ && let Some(dims) = read_avif_dimensions(&data[i + header_size..box_end])
2338fn html_escape(s: &str) -> String {
4086fn html_escape(s: &str) -> String {
2339 s.replace('&', "&")
4087 s.replace('&', "&")
2340 .replace('<', "<")
4088 .replace('<', "<")
@@ -2450,30 +4198,49 @@ fn vlq_encode(value: i64, out: &mut String) {
2453−#[cfg(test)]
4201+/// Check if a specific element kind exists anywhere in the node tree.
2454−mod tests {
4202+fn has_element_kind(nodes: &[Node], target: &ElementKind) -> bool {
2455− use super::*;
4203+ for node in nodes {
2456−
4204+ if let Node::Element(elem) = node {
2457− #[test]
4205+ if elem.kind == *target {
2458− fn a_name_is_a_stable_hash_of_the_style() {
4206+ return true;
2459− // The same in every build and on every platform
4207+ }
2460− assert_eq!(stable_hash(""), 0xf52a_15e9_a9b5_e89b);
4208+ if has_element_kind(&elem.children, target) {
2461− assert_eq!(hash_digits(35, 3), "z00");
4209+ return true;
2462− assert_eq!(hash_digits(u64::MAX, 13), "fsgs46211e5w3");
4210+ }
2466− fn a_name_taken_in_the_file_takes_more_digits() {
4214+}
2467− // These two styles' hashes end in the same 7 digits
4215+
2468− let mut styles = StyleCollector::new();
4216+/// Collect unique external domains from generated HTML for DNS prefetch hints.
2469− let first = styles.get_class("width:129555px;".into(), Vec::new(), String::new());
4217+fn collect_dns_prefetch(html: &str, dev: bool) -> String {
2470− let second = styles.get_class("width:170577px;".into(), Vec::new(), String::new());
4218+ let mut domains = Vec::new();
2471− let (first, second) = (first.unwrap(), second.unwrap());
4219+ let mut rest = html;
2472− assert_eq!(first.len(), 3 + CLASS_DIGITS, "{first}");
4220+ while let Some(pos) = rest.find("https://") {
2473− assert_eq!(second.len(), 3 + CLASS_DIGITS + 1, "{second}");
4221+ let start = pos + 8; // skip "https://"
2474− assert!(second.starts_with(&first), "{first} {second}");
4222+ rest = &rest[start..];
2475− // The same style gets the name it got before
4223+ let end = rest
2476− let again = styles.get_class("width:170577px;".into(), Vec::new(), String::new());
4224+ .find(['/', '"', '\'', ' ', '>', ')'])
2477− assert_eq!(again.as_deref(), Some(second.as_str()));
4225+ .unwrap_or(rest.len());
4226+ let domain = &rest[..end];
4227+ if !domain.is_empty() && domain.contains('.') && !domains.contains(&domain.to_string()) {
4228+ domains.push(domain.to_string());
4231+ let mut out = String::new();
4232+ for domain in &domains {
4234+ out.push_str(&format!(
4235+ "<link rel=\"dns-prefetch\" href=\"//{}\">\n",
4239+ out.push_str(&format!(
4240+ "<link rel=\"dns-prefetch\" href=\"//{}\">",