Add :heading and :heading() pseudo-classes

zcorpan · web-flow · commit 65dc095e4443 · 2025-08-12T01:30:11.000+02:00
Fixes #11412.
diff --git a/source b/source
@@ -76365,6 +76365,17 @@ Demos:
     contains <var>identifier</var>.</p>
    </dd>
 
+   <dt><dfn selector noexport data-x="selector-heading">:heading</dfn></dt>
+   <dd><p>The <code data-x="selector-heading">:heading</code> pseudo-class must match all
+   <code>h1</code>, <code>h2</code>, <code>h3</code>, <code>h4</code>, <code>h5</code>, and
+   <code>h6</code> elements.</p></dd>
+
+   <dt><dfn selector noexport data-x="selector-heading-functional">:heading(<var>An+B</var>#)</dfn></dt>
+   <dd><p>The <code data-x="selector-heading-functional">:heading(<var>An+B</var>#)</code>
+   pseudo-class must match all <code>h1</code>, <code>h2</code>, <code>h3</code>, <code>h4</code>,
+   <code>h5</code>, and <code>h6</code> elements that have a <span>heading level</span> among
+   <var>An+B</var>. <ref>CSSSYNTAX</ref> <ref>CSSVALUES</ref></p></dd>
+
    <dt><dfn selector noexport><code data-x="selector-playing">:playing</code></dfn></dt>
    <dd>
     <p>The <code data-x="selector-playing">:playing</code> <span>pseudo-class</span> must match all
@@ -137635,9 +137646,9 @@ br[clear=all i], br[clear=both i] { clear: both; }</code></pre>
 [dir]:dir(rtl), bdi:dir(rtl) { direction: rtl; }
 
 address, blockquote, center, div, figure, figcaption, footer, form, header, hr,
-legend, listing, main, p, plaintext, pre, summary, xmp, article, aside, h1, h2,
-h3, h4, h5, h6, hgroup, nav, section, search, table, caption, colgroup, col,
-thead, tbody, tfoot, tr, td, th, dir, dd, dl, dt, menu, ol, ul, li, bdi, output,
+legend, listing, main, p, plaintext, pre, summary, xmp, article, aside,
+:heading, hgroup, nav, section, search, table, caption, colgroup, col, thead,
+tbody, tfoot, tr, td, th, dir, dd, dl, dt, menu, ol, ul, li, bdi, output,
 [dir=ltr i], [dir=rtl i], [dir=auto i] {
   unicode-bidi: isolate; <!-- anything that's similar to display:block, plus <bdi>, <output>, and dir="" -->
 }
@@ -137672,9 +137683,9 @@ input[dir=auto i]:is([type=search i], [type=tel i], [type=url i],
   <pre><code class="css">@namespace "http://www.w3.org/1999/xhtml";
 
 address, blockquote, center, div, figure, figcaption, footer, form, header, hr,
-legend, listing, main, p, plaintext, pre, summary, xmp, article, aside, h1, h2,
-h3, h4, h5, h6, hgroup, nav, section, search, table, caption, colgroup, col,
-thead, tbody, tfoot, tr, td, th, dir, dd, dl, dt, menu, ol, ul, li, [dir=ltr i],
+legend, listing, main, p, plaintext, pre, summary, xmp, article, aside,
+:heading, hgroup, nav, section, search, table, caption, colgroup, col, thead,
+tbody, tfoot, tr, td, th, dir, dd, dl, dt, menu, ol, ul, li, [dir=ltr i],
 [dir=rtl i], [dir=auto i], *|* {
   unicode-bidi: bidi-override;
 }
@@ -137688,7 +137699,7 @@ textarea {
 
   <pre><code class="css">@namespace "http://www.w3.org/1999/xhtml";
 
-article, aside, h1, h2, h3, h4, h5, h6, hgroup, nav, section {
+article, aside, :heading, hgroup, nav, section {
   display: block;<!-- see also unicode-bidi: isolate rules-->
 }
 
