diff --git a/docs/app/docs-infra/components/code-highlighter/demos/code-highlight-idle/BasicCode.tsx b/docs/app/docs-infra/components/code-highlighter/demos/code-highlight-idle/BasicCode.tsx
index a75d04ead..96be59ce7 100644
--- a/docs/app/docs-infra/components/code-highlighter/demos/code-highlight-idle/BasicCode.tsx
+++ b/docs/app/docs-infra/components/code-highlighter/demos/code-highlight-idle/BasicCode.tsx
@@ -2,5 +2,5 @@ import * as React from 'react';
 import { Code } from './Code';
 
 export function BasicCode() {
-  return <Code fileName="hello.js">{`console.log('Hello, world!');`}</Code>;
+  return <Code fileName="greeting.js">{`console.log('Hello, world!');`}</Code>;
 }
diff --git a/docs/app/docs-infra/components/code-highlighter/demos/demo-fallback-all-files/DemoContentLoading.tsx b/docs/app/docs-infra/components/code-highlighter/demos/demo-fallback-all-files/DemoContentLoading.tsx
index 936980ce8..83422fa5d 100644
--- a/docs/app/docs-infra/components/code-highlighter/demos/demo-fallback-all-files/DemoContentLoading.tsx
+++ b/docs/app/docs-infra/components/code-highlighter/demos/demo-fallback-all-files/DemoContentLoading.tsx
@@ -25,8 +25,8 @@ export function DemoContentLoading(props: ContentLoadingProps<object>) {
 
   return (
     <div>
-      {Object.keys(props.extraSource || {}).map((slug) => (
-        <span key={slug} id={slug} className={styles.fileRefs} />
+      {Object.keys(props.extraSource || {}).map((fileName) => (
+        <span key={fileName} className={styles.fileRefs} />
       ))}
       <div className={styles.container}>
         <div className={styles.demoSection}>{props.component}</div>
diff --git a/docs/app/docs-infra/components/code-highlighter/demos/demo-fallback-all-variants/DemoContentLoading.tsx b/docs/app/docs-infra/components/code-highlighter/demos/demo-fallback-all-variants/DemoContentLoading.tsx
index 069c8d4aa..88db9f672 100644
--- a/docs/app/docs-infra/components/code-highlighter/demos/demo-fallback-all-variants/DemoContentLoading.tsx
+++ b/docs/app/docs-infra/components/code-highlighter/demos/demo-fallback-all-variants/DemoContentLoading.tsx
@@ -38,8 +38,8 @@ export function DemoContentLoading(props: ContentLoadingProps<object>) {
 
   return (
     <div>
-      {Object.keys(props.extraSource || {}).map((slug) => (
-        <span key={slug} id={slug} className={styles.fileRefs} />
+      {Object.keys(props.extraSource || {}).map((fileName) => (
+        <span key={fileName} className={styles.fileRefs} />
       ))}
       <div className={styles.container}>
         <div className={styles.demoSection}>{props.component}</div>
diff --git a/docs/app/docs-infra/components/code-highlighter/demos/demo-fallback/DemoContentLoading.tsx b/docs/app/docs-infra/components/code-highlighter/demos/demo-fallback/DemoContentLoading.tsx
index c9f806ced..3ac2e36fc 100644
--- a/docs/app/docs-infra/components/code-highlighter/demos/demo-fallback/DemoContentLoading.tsx
+++ b/docs/app/docs-infra/components/code-highlighter/demos/demo-fallback/DemoContentLoading.tsx
@@ -24,8 +24,8 @@ export function DemoContentLoading(props: ContentLoadingProps<object>) {
 
   return (
     <div>
-      {Object.keys(props.extraSource || {}).map((slug) => (
-        <span key={slug} id={slug} className={styles.fileRefs} />
+      {Object.keys(props.extraSource || {}).map((fileName) => (
+        <span key={fileName} className={styles.fileRefs} />
       ))}
       <div className={styles.container}>
         <div className={styles.demoSection}>{props.component}</div>
diff --git a/docs/app/docs-infra/components/code-highlighter/demos/demo/demo-basic/index.ts b/docs/app/docs-infra/components/code-highlighter/demos/demo/demo-basic/index.ts
index 6406561d5..8eb2a01e1 100644
--- a/docs/app/docs-infra/components/code-highlighter/demos/demo/demo-basic/index.ts
+++ b/docs/app/docs-infra/components/code-highlighter/demos/demo/demo-basic/index.ts
@@ -1,4 +1,6 @@
 import { CheckboxBasic } from './CheckboxBasic';
 import { createDemo } from '../../createDemo';
 
-export const DemoCheckboxBasic = createDemo(import.meta.url, CheckboxBasic);
+export const DemoCheckboxBasic = createDemo(import.meta.url, CheckboxBasic, {
+  slug: 'interactive-demo-basic',
+});
diff --git a/docs/app/docs-infra/hooks/use-copier/demos/text-input-copy/TextInputCopy.tsx b/docs/app/docs-infra/hooks/use-copier/demos/text-input-copy/TextInputCopy.tsx
index a9e2719bc..d7fc7c301 100644
--- a/docs/app/docs-infra/hooks/use-copier/demos/text-input-copy/TextInputCopy.tsx
+++ b/docs/app/docs-infra/hooks/use-copier/demos/text-input-copy/TextInputCopy.tsx
@@ -15,6 +15,7 @@ export function TextInputCopy() {
         onChange={(event) => setText(event.target.value)}
         className={styles.input}
         placeholder="Enter text to copy..."
+        aria-label="Text to copy"
       />
       <button type="button" onClick={copy} className={styles.button}>
         {recentlySuccessful ? '✓ Copied!' : 'Copy'}
diff --git a/docs/app/docs-infra/hooks/use-types/demos/TypesTable.tsx b/docs/app/docs-infra/hooks/use-types/demos/TypesTable.tsx
index 3768c8299..62e94c162 100644
--- a/docs/app/docs-infra/hooks/use-types/demos/TypesTable.tsx
+++ b/docs/app/docs-infra/hooks/use-types/demos/TypesTable.tsx
@@ -480,7 +480,7 @@ function ClassDoc(props: { type: EnhancedClassTypeMeta }) {
             {method.returnValue && (
               <div>
                 <strong>Returns:</strong> {method.returnValue}
-                {method.returnValueDescription && <span> — {method.returnValueDescription}</span>}
+                {method.returnValueDescription && <div> — {method.returnValueDescription}</div>}
               </div>
             )}
           </div>
diff --git a/docs/components/Checkbox/index.tsx b/docs/components/Checkbox/index.tsx
index 722154fb4..b290857f3 100644
--- a/docs/components/Checkbox/index.tsx
+++ b/docs/components/Checkbox/index.tsx
@@ -14,14 +14,16 @@ type CheckboxProps = {
 
 export function Checkbox({ defaultChecked, name = 'checkbox', className, style }: CheckboxProps) {
   const [checked, setChecked] = React.useState(defaultChecked);
+  const id = React.useId();
+  const inputId = `${id}-${name}-input`;
   const onChange = React.useCallback(() => {
     setChecked((prev) => !prev);
   }, []);
 
   return (
-    <label className={styles.checkbox} htmlFor={`${name}-input`}>
+    <label className={styles.checkbox} htmlFor={inputId}>
       <input
-        id={`${name}-input`}
+        id={inputId}
         type="checkbox"
         name={name}
         checked={checked}
diff --git a/docs/components/DemoPerformanceContentLoading/DemoPerformanceContentLoading.tsx b/docs/components/DemoPerformanceContentLoading/DemoPerformanceContentLoading.tsx
index 5802412ec..62ae2c508 100644
--- a/docs/components/DemoPerformanceContentLoading/DemoPerformanceContentLoading.tsx
+++ b/docs/components/DemoPerformanceContentLoading/DemoPerformanceContentLoading.tsx
@@ -24,8 +24,8 @@ export function DemoPerformanceContentLoading(props: ContentLoadingProps<object>
 
   return (
     <div>
-      {Object.keys(props.extraSource || {}).map((slug) => (
-        <span key={slug} id={slug} className={styles.fileRefs} />
+      {Object.keys(props.extraSource || {}).map((fileName) => (
+        <span key={fileName} className={styles.fileRefs} />
       ))}
       <div className={styles.container}>
         <div className={styles.demoSection}></div>
diff --git a/docs/components/ExpandingBox/ExpandingBox.css b/docs/components/ExpandingBox/ExpandingBox.css
index 60214495b..c8ffd0127 100644
--- a/docs/components/ExpandingBox/ExpandingBox.css
+++ b/docs/components/ExpandingBox/ExpandingBox.css
@@ -9,7 +9,7 @@
   min-height: 0;
 }
 
-.expanding-box-content > div:nth-child(2) {
+.expanding-box-content > span:nth-child(2) {
   display: flex;
   flex-direction: column;
   flex: 1;
@@ -23,7 +23,7 @@
   view-transition-class: closing;
 }
 
-.expanding-box-content > div:first-child {
+.expanding-box-content > span:first-child {
   position: absolute;
   left: 0;
   right: 0;
@@ -36,11 +36,11 @@
   transition: transform ease-in-out 150ms;
 }
 
-:hover:not(:focus-visible) > .expanding-box-content[data-collapsed='true'] > div:first-child {
+:hover:not(:focus-visible) > .expanding-box-content[data-collapsed='true'] > span:first-child {
   transform: scale(1.04);
 }
 
-.expanding-box-content[data-collapsed='true'] > div:first-child::after {
+.expanding-box-content[data-collapsed='true'] > span:first-child::after {
   content: '';
   display: block;
   position: absolute;
@@ -51,7 +51,7 @@
   view-transition-name: expanding-box-focus-outline;
 }
 
-:focus-visible > .expanding-box-content > div:first-child::after {
+:focus-visible > .expanding-box-content > span:first-child::after {
   content: '';
   outline-color: #8e4ec6;
   outline-offset: 1px;
@@ -60,38 +60,38 @@
   border-radius: 6px;
 }
 
-.expanding-box-content[data-active='true'] > div:first-child {
+.expanding-box-content[data-active='true'] > span:first-child {
   view-transition-name: expanding-box-side-borders;
 }
 
-.expanding-box-content[data-active='true'][data-collapsed='true'] > div:first-child {
+.expanding-box-content[data-active='true'][data-collapsed='true'] > span:first-child {
   view-transition-class: closing;
 }
 
-.expanding-box-content[data-active='true'] > div > :nth-child(1) {
+.expanding-box-content[data-active='true'] > span > :nth-child(1) {
   view-transition-name: expanding-box-main-content;
 }
 
-.expanding-box-content[data-active='true'][data-collapsed='true'] > div > :nth-child(1) {
+.expanding-box-content[data-active='true'][data-collapsed='true'] > span > :nth-child(1) {
   view-transition-class: closing;
 }
 
-.expanding-box-content[data-active='true'] > div > :nth-child(1) .expanding-box-content-right {
+.expanding-box-content[data-active='true'] > span > :nth-child(1) .expanding-box-content-right {
   view-transition-name: expanding-box-main-content-right;
 }
 
 .expanding-box-content[data-active='true'][data-collapsed='true']
-  > div
+  > span
   > :nth-child(1)
   .expanding-box-content-right {
   view-transition-class: closing;
 }
 
-.expanding-box-content[data-active='true'] > div > :nth-child(2) {
+.expanding-box-content[data-active='true'] > span > :nth-child(2) {
   view-transition-name: expanding-box-extra-content;
 }
 
-.expanding-box-content[data-active='true'][data-collapsed='true'] > div > :nth-child(2) {
+.expanding-box-content[data-active='true'][data-collapsed='true'] > span > :nth-child(2) {
   view-transition-class: closing;
 }
 
diff --git a/docs/components/ExpandingBox/ExpandingBox.tsx b/docs/components/ExpandingBox/ExpandingBox.tsx
index 1bf340d62..85ecd8163 100644
--- a/docs/components/ExpandingBox/ExpandingBox.tsx
+++ b/docs/components/ExpandingBox/ExpandingBox.tsx
@@ -14,35 +14,35 @@ export function ExpandingBox({
 }) {
   return (
     <React.Fragment>
-      <div
+      <span
         className="expanding-box-head"
         data-active={Boolean(isActive)}
         data-collapsed={Boolean(isCollapsed)}
       >
-        <div />
-        <div />
-        <div />
-      </div>
-      <div
+        <span />
+        <span />
+        <span />
+      </span>
+      <span
         className="expanding-box-content"
         data-active={Boolean(isActive)}
         data-collapsed={Boolean(isCollapsed)}
       >
-        <div />
-        <div className={className}>
+        <span />
+        <span className={className}>
           {children}
-          <div className="expanding-box-extra" />
-        </div>
-      </div>
-      <div
+          <span className="expanding-box-extra" />
+        </span>
+      </span>
+      <span
         className="expanding-box-foot"
         data-active={Boolean(isActive)}
         data-collapsed={Boolean(isCollapsed)}
       >
-        <div />
-        <div />
-        <div />
-      </div>
+        <span />
+        <span />
+        <span />
+      </span>
     </React.Fragment>
   );
 }
diff --git a/docs/components/Search/SearchButton.tsx b/docs/components/Search/SearchButton.tsx
index a51f360b8..d58e9a2aa 100644
--- a/docs/components/Search/SearchButton.tsx
+++ b/docs/components/Search/SearchButton.tsx
@@ -14,18 +14,18 @@ export function SearchButton({ onClick, isDialogOpen, enableKeyboardShortcut }:
   return (
     <Button onClick={onClick} className={`${styles.button} ${isDialogOpen ? styles.hidden : ''}`}>
       <ExpandingBox isActive={!isDialogOpen} isCollapsed={true} className={styles.content}>
-        <div className={styles.wrapper}>
-          <div className={styles.buttonContent}>
+        <span className={styles.wrapper}>
+          <span className={styles.buttonContent}>
             <Search className={styles.icon} />
             <span className={styles.text}>Search</span>
-          </div>
+          </span>
           {enableKeyboardShortcut && (
-            <div className={`expanding-box-content-right ${styles.shortcut}`}>
+            <span className={`expanding-box-content-right ${styles.shortcut}`}>
               <kbd className={`${styles.kbd} ${styles.kbdCmd}`}>⌘</kbd>
               <kbd className={styles.kbd}>K</kbd>
-            </div>
+            </span>
           )}
-        </div>
+        </span>
       </ExpandingBox>
     </Button>
   );
diff --git a/docs/components/Search/SearchInput.tsx b/docs/components/Search/SearchInput.tsx
index 4045206e7..9596aa6f6 100644
--- a/docs/components/Search/SearchInput.tsx
+++ b/docs/components/Search/SearchInput.tsx
@@ -18,6 +18,7 @@ export function SearchInput({ inputRef, onEscapeClick, enableKeyboardShortcut }:
         id="search-input"
         ref={inputRef}
         placeholder="Search"
+        aria-label="Search"
         className={styles.input}
       />
 
diff --git a/docs/scripts/reportBrokenLinks.mts b/docs/scripts/reportBrokenLinks.mts
index 1b4570946..e43d38bb6 100644
--- a/docs/scripts/reportBrokenLinks.mts
+++ b/docs/scripts/reportBrokenLinks.mts
@@ -8,6 +8,7 @@ async function main() {
     ignoredPaths: [],
     // CSS selectors for content to ignore during link checking
     ignoredContent: [],
+    htmlValidate: true,
   });
 
   process.exit(issues.length);
diff --git a/packages/code-infra/package.json b/packages/code-infra/package.json
index 3fd013108..3615c0614 100644
--- a/packages/code-infra/package.json
+++ b/packages/code-infra/package.json
@@ -111,6 +111,7 @@
     "git-url-parse": "^16.1.0",
     "globals": "^17.4.0",
     "globby": "^16.1.1",
+    "html-validate": "^10.11.2",
     "minimatch": "^10.2.4",
     "node-html-parser": "^7.1.0",
     "open": "^11.0.0",
diff --git a/packages/code-infra/src/brokenLinksChecker/__fixtures__/static-site/index.html b/packages/code-infra/src/brokenLinksChecker/__fixtures__/static-site/index.html
index c9ba541e5..c79573ba0 100644
--- a/packages/code-infra/src/brokenLinksChecker/__fixtures__/static-site/index.html
+++ b/packages/code-infra/src/brokenLinksChecker/__fixtures__/static-site/index.html
@@ -22,6 +22,7 @@ <h1>Test Site Home</h1>
         <li><a href="/page-with-api-links.html">Page with API Links</a></li>
         <li><a href="/example.md">Example Markdown</a></li>
         <li><a href="/unclosed-tags.html">Page with Unclosed Tags</a></li>
+        <li><a href="/invalid-html.html">Invalid HTML Page</a></li>
       </ul>
     </nav>
   </body>
diff --git a/packages/code-infra/src/brokenLinksChecker/__fixtures__/static-site/invalid-html.html b/packages/code-infra/src/brokenLinksChecker/__fixtures__/static-site/invalid-html.html
new file mode 100644
index 000000000..fd4f01f73
--- /dev/null
+++ b/packages/code-infra/src/brokenLinksChecker/__fixtures__/static-site/invalid-html.html
@@ -0,0 +1,15 @@
+<!DOCTYPE html>
+<html lang="en">
+  <head>
+    <meta charset="UTF-8" />
+    <title>Invalid HTML Page</title>
+  </head>
+  <body>
+    <h1>Invalid HTML</h1>
+    <!-- Duplicate ID (violates no-duplicate-id rule) -->
+    <div id="dup">First</div>
+    <div id="dup">Second</div>
+    <!-- Raw ampersand (violates no-raw-characters rule) -->
+    <p>Tom & Jerry</p>
+  </body>
+</html>
diff --git a/packages/code-infra/src/brokenLinksChecker/crawlWorker.mjs b/packages/code-infra/src/brokenLinksChecker/crawlWorker.mjs
new file mode 100644
index 000000000..a2e55ab39
--- /dev/null
+++ b/packages/code-infra/src/brokenLinksChecker/crawlWorker.mjs
@@ -0,0 +1,173 @@
+import { workerData, parentPort } from 'node:worker_threads';
+import { parse } from 'node-html-parser';
+import contentType from 'content-type';
+import { HtmlValidate, StaticConfigLoader, staticResolver } from 'html-validate';
+import { unified } from 'unified';
+import remarkParse from 'remark-parse';
+import remarkGfm from 'remark-gfm';
+import remarkRehype from 'remark-rehype';
+import rehypeSlug from 'rehype-slug';
+import rehypeStringify from 'rehype-stringify';
+
+/** @type {import('./index.mjs').CrawlWorkerInput} */
+const { pageUrl, options } = workerData;
+
+/**
+ * Posts the crawl result back to the parent thread.
+ * @param {import('./index.mjs').CrawlWorkerOutput} output
+ */
+function postResult(output) {
+  if (!parentPort) {
+    throw new Error('crawlWorker must be run as a worker thread');
+  }
+  parentPort.postMessage(output);
+}
+
+/**
+ * Computes the accessible name of an element according to ARIA rules.
+ * @param {import('node-html-parser').HTMLElement | null} elm
+ * @param {import('node-html-parser').HTMLElement} ownerDocument
+ * @returns {string}
+ */
+function getAccessibleName(elm, ownerDocument) {
+  if (!elm) {
+    return '';
+  }
+
+  const ariaLabel = elm.getAttribute('aria-label')?.trim();
+  if (ariaLabel) {
+    return ariaLabel;
+  }
+
+  const labelledby = elm.getAttribute('aria-labelledby');
+  if (labelledby) {
+    const labels = [];
+    for (const id of labelledby.split(/\s+/)) {
+      const label = getAccessibleName(ownerDocument.getElementById(id), ownerDocument);
+      if (label) {
+        labels.push(label);
+      }
+    }
+    const label = labels.join(' ').trim();
+    if (label) {
+      return label;
+    }
+  }
+
+  if (elm.id) {
+    const label = ownerDocument.querySelector(`label[for="${elm.id}"]`);
+    if (label) {
+      return getAccessibleName(label, ownerDocument);
+    }
+  }
+
+  if (elm.tagName === 'IMG') {
+    const alt = elm.getAttribute('alt')?.trim();
+    if (alt) {
+      return alt;
+    }
+  }
+
+  return elm.innerText.trim();
+}
+
+/**
+ * Converts markdown content to HTML using unified pipeline.
+ * @param {string} markdown
+ * @returns {Promise<string>}
+ */
+async function markdownToHtml(markdown) {
+  const result = await unified()
+    .use(remarkParse)
+    .use(remarkGfm)
+    .use(remarkRehype)
+    .use(rehypeSlug)
+    .use(rehypeStringify)
+    .process(markdown);
+  return String(result);
+}
+
+const res = await fetch(new URL(pageUrl, options.host));
+
+const contentTypeHeader = res.headers.get('content-type');
+let type = 'text/html';
+
+if (contentTypeHeader) {
+  try {
+    const parsed = contentType.parse(contentTypeHeader);
+    type = parsed.type;
+  } catch {
+    // invalid content-type, default to text/html
+  }
+}
+
+/** @type {import('./index.mjs').CrawlWorkerPageData} */
+const pageData = {
+  url: pageUrl,
+  status: res.status,
+  targets: [],
+  contentType: type,
+};
+
+if (pageData.status < 200 || pageData.status >= 400) {
+  postResult({ pageData, links: [], htmlValidateResults: null });
+} else if (type.startsWith('image/') || (type !== 'text/html' && type !== 'text/markdown')) {
+  postResult({ pageData, links: [], htmlValidateResults: null });
+} else {
+  const rawContent = await res.text();
+
+  const content = type === 'text/markdown' ? await markdownToHtml(rawContent) : rawContent;
+
+  const dom = parse(content, { parseNoneClosedTags: true });
+
+  // Extract targets
+  for (const target of dom.querySelectorAll('*[id]')) {
+    if (!options.ignoredTargets.has(target.id)) {
+      pageData.targets.push(`#${target.id}`);
+    }
+  }
+
+  // Extract links
+  let ignoredSelector = ':not(*)';
+  if (options.ignoredContent.length > 0) {
+    ignoredSelector = Array.from(options.ignoredContent)
+      .flatMap((selector) => [selector, `${selector} *`])
+      .join(',');
+  }
+  const linksSelector = `a[href]:not(${ignoredSelector})`;
+
+  const links = dom.querySelectorAll(linksSelector).map((a) => ({
+    src: pageUrl,
+    text: getAccessibleName(a, dom),
+    href: a.getAttribute('href') ?? '',
+    contentType: type,
+  }));
+
+  // HTML validation
+  /** @type {{ pageUrl: string, results: import('html-validate').Result[] } | null} */
+  let htmlValidateResults = null;
+  if (options.htmlValidate && type === 'text/html') {
+    const muiHtmlValidateResolver = staticResolver({
+      configs: {
+        'mui:recommended': {
+          extends: ['html-validate:standard', 'html-validate:document', 'html-validate:browser'],
+          rules: {
+            // TODO: Enable when subresource integrity is adopted across projects
+            'require-sri': 'off',
+          },
+        },
+      },
+    });
+
+    const htmlValidator = new HtmlValidate(
+      new StaticConfigLoader([muiHtmlValidateResolver], options.htmlValidate),
+    );
+
+    const report = await htmlValidator.validateString(rawContent, pageUrl);
+    if (!report.valid) {
+      htmlValidateResults = { pageUrl, results: report.results };
+    }
+  }
+
+  postResult({ pageData, links, htmlValidateResults });
+}
diff --git a/packages/code-infra/src/brokenLinksChecker/index.mjs b/packages/code-infra/src/brokenLinksChecker/index.mjs
index 64718cec2..d22161eac 100644
--- a/packages/code-infra/src/brokenLinksChecker/index.mjs
+++ b/packages/code-infra/src/brokenLinksChecker/index.mjs
@@ -1,21 +1,17 @@
 /* eslint-disable no-console */
 import { execaCommand } from 'execa';
 import timers from 'node:timers/promises';
-import { parse } from 'node-html-parser';
 import * as fs from 'node:fs/promises';
 import * as path from 'node:path';
+import { pathToFileURL } from 'node:url';
 import chalk from 'chalk';
 import { Transform } from 'node:stream';
-import contentType from 'content-type';
-import { unified } from 'unified';
-import remarkParse from 'remark-parse';
-import remarkGfm from 'remark-gfm';
-import remarkRehype from 'remark-rehype';
-import rehypeSlug from 'rehype-slug';
-import rehypeStringify from 'rehype-stringify';
+import { Worker } from 'node:worker_threads';
 
 const DEFAULT_CONCURRENCY = 4;
 
+const crawlWorkerUrl = new URL('./crawlWorker.mjs', import.meta.url);
+
 /**
  * Creates a Transform stream that prefixes each line with a given string.
  * Useful for distinguishing server logs from other output.
@@ -105,6 +101,30 @@ function deserializeLinkStructure(data) {
   return linkStructure;
 }
 
+/**
+ * Input data passed to the crawl worker via workerData.
+ * @typedef {Object} CrawlWorkerInput
+ * @property {string} pageUrl - The page URL to crawl
+ * @property {ResolvedCrawlOptions} options - Fully resolved crawl options
+ */
+
+/**
+ * Serialized page data returned by the crawl worker (uses arrays instead of Sets for structured clone).
+ * @typedef {Object} CrawlWorkerPageData
+ * @property {string} url - The normalized page URL
+ * @property {number} status - HTTP status code
+ * @property {string[]} targets - Array of anchor targets (e.g., '#intro')
+ * @property {string} contentType - Content-type of the page
+ */
+
+/**
+ * Output message posted by the crawl worker.
+ * @typedef {Object} CrawlWorkerOutput
+ * @property {CrawlWorkerPageData} pageData - Serialized page data
+ * @property {Link[]} links - Links discovered on the page
+ * @property {{ pageUrl: string, results: import('html-validate').Result[] } | null} htmlValidateResults - HTML validation results, or null if validation was skipped/passed
+ */
+
 /**
  * Data about a crawled page including its URL, HTTP status, and available link targets.
  * @typedef {Object} PageData
@@ -131,77 +151,6 @@ async function writePagesToFile(pages, outPath) {
   await fs.writeFile(outPath, JSON.stringify(fileContent, null, 2), 'utf-8');
 }
 
-/**
- * Computes the accessible name of an element according to ARIA rules.
- * Polyfill for `node.computedName` available only in Chrome v112+.
- * Checks in order: aria-label, aria-labelledby, label[for], img alt, innerText.
- * @param {import('node-html-parser').HTMLElement | null} elm - Element to compute name for
- * @param {import('node-html-parser').HTMLElement} ownerDocument - Document containing the element
- * @returns {string} The computed accessible name, or empty string if none found
- */
-function getAccessibleName(elm, ownerDocument) {
-  if (!elm) {
-    return '';
-  }
-
-  // 1. aria-label
-  const ariaLabel = elm.getAttribute('aria-label')?.trim();
-  if (ariaLabel) {
-    return ariaLabel;
-  }
-
-  // 2. aria-labelledby
-  const labelledby = elm.getAttribute('aria-labelledby');
-  if (labelledby) {
-    const labels = [];
-    for (const id of labelledby.split(/\s+/)) {
-      const label = getAccessibleName(ownerDocument.getElementById(id), ownerDocument);
-      if (label) {
-        labels.push(label);
-      }
-    }
-    const label = labels.join(' ').trim();
-    if (label) {
-      return label;
-    }
-  }
-
-  // 3. <label for="id">
-  if (elm.id) {
-    const label = ownerDocument.querySelector(`label[for="${elm.id}"]`);
-    if (label) {
-      return getAccessibleName(label, ownerDocument);
-    }
-  }
-
-  // 4. <img alt="">
-  if (elm.tagName === 'IMG') {
-    const alt = elm.getAttribute('alt')?.trim();
-    if (alt) {
-      return alt;
-    }
-  }
-
-  // 5. Fallback: visible text
-  return elm.innerText.trim();
-}
-
-/**
- * Converts markdown content to HTML using unified pipeline.
- * @param {string} markdown - Raw markdown content
- * @returns {Promise<string>} Converted HTML string
- */
-async function markdownToHtml(markdown) {
-  const result = await unified()
-    .use(remarkParse)
-    .use(remarkGfm)
-    .use(remarkRehype)
-    .use(rehypeSlug)
-    .use(rehypeStringify)
-    .process(markdown);
-  return String(result);
-}
-
 /**
  * Generic concurrent task queue with configurable concurrency limit.
  * Processes tasks in FIFO order with a maximum number of concurrent workers.
@@ -402,11 +351,12 @@ function shouldIgnoreLink(link, ignores) {
  * @property {number} [concurrency] - Number of concurrent page fetches (defaults to 4)
  * @property {string[]} [seedUrls] - Starting URLs for the crawl (defaults to ['/'])
  * @property {IgnoreRule[]} [ignores] - Rules to ignore broken links. Each rule can have path, href, contentType, and/or has properties. All specified properties must match (AND logic). Within a property, multiple values use OR logic.
+ * @property {boolean | import('html-validate').ConfigData} [htmlValidate] - Enable HTML validation on crawled pages. `false` (default): disabled. `true`: validate with recommended rules. Object: use as html-validate config (supports `extends: ['mui:recommended']` to reference the default config).
  */
 
 /**
  * Fully resolved configuration with all optional fields filled with defaults.
- * @typedef {Omit<Required<CrawlOptions>, 'ignores'> & { ignores: NormalizedIgnoreRule[] }} ResolvedCrawlOptions
+ * @typedef {Omit<Required<CrawlOptions>, 'ignores' | 'htmlValidate'> & { ignores: NormalizedIgnoreRule[], htmlValidate: import('html-validate').ConfigData | null }} ResolvedCrawlOptions
  */
 
 /**
@@ -422,6 +372,21 @@ function validateIgnoreRule(rule) {
   }
 }
 
+/**
+ * Resolves the htmlValidate option into an html-validate config object or null.
+ * @param {boolean | import('html-validate').ConfigData | undefined} option
+ * @returns {import('html-validate').ConfigData | null}
+ */
+function resolveHtmlValidateConfig(option) {
+  if (!option) {
+    return null;
+  }
+  if (option === true) {
+    return { extends: ['mui:recommended'] };
+  }
+  return option;
+}
+
 /**
  * Resolves partial crawl options by filling in defaults for all optional fields.
  * @param {CrawlOptions} rawOptions - Partial options from user
@@ -447,6 +412,7 @@ function resolveOptions(rawOptions) {
     concurrency: rawOptions.concurrency ?? DEFAULT_CONCURRENCY,
     seedUrls: rawOptions.seedUrls ?? ['/'],
     ignores: normalizedIgnores,
+    htmlValidate: resolveHtmlValidateConfig(rawOptions.htmlValidate),
   };
 }
 
@@ -506,25 +472,42 @@ async function resolveKnownTargets(options) {
 
 /**
  * Represents a broken link or broken link target discovered during crawling.
- * @typedef {Object} Issue
+ * @typedef {Object} BrokenLinkIssue
  * @property {'broken-link' | 'broken-target'} type - Type of issue: 'broken-link' for 404 pages, 'broken-target' for missing anchors
  * @property {string} message - Human-readable description of the issue (e.g., 'Target not found', 'Page returned error 404')
  * @property {Link} link - The link object that has the issue
  */
 
+/**
+ * Represents an HTML validation issue found on a crawled page.
+ * @typedef {Object} HtmlValidateIssue
+ * @property {'html-validate'} type - Issue type discriminator
+ * @property {string} message - Human-readable description of the issue
+ * @property {string} pageUrl - The page URL where the issue was found
+ * @property {string} ruleId - The html-validate rule that triggered this issue (e.g., 'no-dup-id')
+ * @property {number} severity - Severity level (1 = warning, 2 = error)
+ * @property {{ line: number, column: number }} location - Source location of the issue
+ * @property {string | null} selector - DOM selector for the element, or null
+ */
+
+/**
+ * Any issue discovered during crawling.
+ * @typedef {BrokenLinkIssue | HtmlValidateIssue} Issue
+ */
+
 /**
  * Results from a complete crawl operation.
  * @typedef {Object} CrawlResult
  * @property {Set<Link>} links - All links discovered during the crawl
  * @property {Map<string, PageData>} pages - All pages crawled, keyed by normalized URL
- * @property {Issue[]} issues - All broken links and broken targets found
+ * @property {Issue[]} issues - All issues found (broken links, broken targets, and HTML validation issues)
  */
 
 /**
  * Reports broken links to stderr, grouped by source page for better readability.
- * @param {Issue[]} issuesList - Array of issues to report
+ * @param {BrokenLinkIssue[]} issuesList - Array of broken link issues to report
  */
-function reportIssues(issuesList) {
+function reportBrokenLinks(issuesList) {
   if (issuesList.length === 0) {
     return;
   }
@@ -532,7 +515,7 @@ function reportIssues(issuesList) {
   console.error('\nBroken links found:\n');
 
   // Group issues by source URL
-  /** @type {Map<string, Issue[]>} */
+  /** @type {Map<string, BrokenLinkIssue[]>} */
   const issuesBySource = new Map();
   for (const issue of issuesList) {
     const sourceUrl = issue.link.src ?? '(unknown)';
@@ -553,6 +536,39 @@ function reportIssues(issuesList) {
   }
 }
 
+/**
+ * Reports HTML validation issues to stderr, grouped by page URL.
+ * @param {HtmlValidateIssue[]} htmlIssues - Array of HTML validation issues to report
+ */
+function reportHtmlValidation(htmlIssues) {
+  if (htmlIssues.length === 0) {
+    return;
+  }
+
+  console.error('\nHTML validation issues:\n');
+
+  // Group by page URL
+  /** @type {Map<string, HtmlValidateIssue[]>} */
+  const issuesByPage = new Map();
+  for (const issue of htmlIssues) {
+    const pageIssues = issuesByPage.get(issue.pageUrl) ?? [];
+    if (pageIssues.length === 0) {
+      issuesByPage.set(issue.pageUrl, pageIssues);
+    }
+    pageIssues.push(issue);
+  }
+
+  for (const [pageUrl, pageIssues] of issuesByPage.entries()) {
+    console.error(`Page ${chalk.cyan(pageUrl)}:`);
+    for (const issue of pageIssues) {
+      const severityLabel = issue.severity === 2 ? chalk.red('error') : chalk.yellow('warning');
+      console.error(
+        `  ${issue.location.line}:${issue.location.column}  ${severityLabel}  ${issue.message}  ${chalk.gray(issue.ruleId)}`,
+      );
+    }
+  }
+}
+
 /**
  * Crawls a website starting from seed URLs, discovering all internal links and checking for broken links/targets.
  * @param {CrawlOptions} rawOptions - Configuration options for the crawl
@@ -594,6 +610,35 @@ export async function crawl(rawOptions) {
   const crawledPages = new Map();
   /** @type {Set<Link>} */
   const crawledLinks = new Set();
+  /** @type {Issue[]} */
+  const issues = [];
+  /**
+   * Spawns a crawl worker for a page URL.
+   * @param {string} pageUrl - The page URL to crawl
+   * @returns {Promise<{ pageData: PageData, links: Link[], htmlValidateResults: CrawlWorkerOutput['htmlValidateResults'] }>}
+   */
+  function crawlInWorker(pageUrl) {
+    return new Promise((resolve, reject) => {
+      /** @type {CrawlWorkerInput} */
+      const input = { pageUrl, options };
+      const worker = new Worker(crawlWorkerUrl, {
+        workerData: input,
+      });
+      worker.on('message', (/** @type {CrawlWorkerOutput} */ msg) => {
+        resolve({
+          pageData: {
+            url: msg.pageData.url,
+            status: msg.pageData.status,
+            targets: new Set(msg.pageData.targets),
+            contentType: msg.pageData.contentType,
+          },
+          links: msg.links,
+          htmlValidateResults: msg.htmlValidateResults,
+        });
+      });
+      worker.on('error', (err) => reject(err));
+    });
+  }
 
   const queue = new Queue(async (/** @type {Link} */ link) => {
     crawledLinks.add(link);
@@ -611,78 +656,30 @@ export async function crawl(rawOptions) {
       return;
     }
 
-    const pagePromise = Promise.resolve().then(async () => {
-      console.log(`Crawling ${chalk.cyan(pageUrl)}...`);
-      const res = await fetch(new URL(pageUrl, options.host));
-
-      const contentTypeHeader = res.headers.get('content-type');
-      let type = 'text/html';
-
-      if (contentTypeHeader) {
-        try {
-          const parsed = contentType.parse(contentTypeHeader);
-          type = parsed.type;
-        } catch {
-          console.warn(
-            chalk.yellow(`Warning: ${pageUrl} returned invalid content-type: ${contentTypeHeader}`),
-          );
-        }
-      }
-
-      /** @type {PageData} */
-      const pageData = {
-        url: pageUrl,
-        status: res.status,
-        targets: new Set(),
-        contentType: type,
-      };
-
-      if (pageData.status < 200 || pageData.status >= 400) {
-        console.warn(chalk.yellow(`Warning: ${pageUrl} returned status ${pageData.status}`));
-        return pageData;
-      }
-
-      if (type.startsWith('image/')) {
-        // Skip images
-        return pageData;
-      }
-
-      if (type !== 'text/html' && type !== 'text/markdown') {
-        console.warn(chalk.yellow(`Warning: ${pageUrl} returned non-HTML content-type: ${type}`));
-        return pageData;
-      }
-
-      const rawContent = await res.text();
-      const content = type === 'text/markdown' ? await markdownToHtml(rawContent) : rawContent;
-
-      const dom = parse(content, { parseNoneClosedTags: true });
-
-      let ignoredSelector = ':not(*)'; // matches nothing
-      if (options.ignoredContent.length > 0) {
-        ignoredSelector = Array.from(options.ignoredContent)
-          .flatMap((selector) => [selector, `${selector} *`])
-          .join(',');
-      }
-      const linksSelector = `a[href]:not(${ignoredSelector})`;
-
-      const pageLinks = dom.querySelectorAll(linksSelector).map((a) => ({
-        src: pageUrl,
-        text: getAccessibleName(a, dom),
-        href: a.getAttribute('href') ?? '',
-        contentType: type,
-      }));
-
-      for (const target of dom.querySelectorAll('*[id]')) {
-        if (!options.ignoredTargets.has(target.id)) {
-          pageData.targets.add(`#${target.id}`);
+    console.log(`Crawling ${chalk.cyan(pageUrl)}...`);
+    const workerPromise = crawlInWorker(pageUrl);
+    const pagePromise = workerPromise.then((result) => {
+      if (result.htmlValidateResults) {
+        for (const validationResult of result.htmlValidateResults.results) {
+          for (const msg of validationResult.messages) {
+            issues.push({
+              type: 'html-validate',
+              message: msg.message,
+              pageUrl: result.htmlValidateResults.pageUrl,
+              ruleId: msg.ruleId,
+              severity: msg.severity,
+              location: { line: msg.line, column: msg.column },
+              selector: msg.selector,
+            });
+          }
         }
       }
 
-      for (const pageLink of pageLinks) {
-        queue.add(pageLink);
+      for (const discoveredLink of result.links) {
+        queue.add(discoveredLink);
       }
 
-      return pageData;
+      return result.pageData;
     });
 
     crawledPages.set(pageUrl, pagePromise);
@@ -711,10 +708,6 @@ export async function crawl(rawOptions) {
     await writePagesToFile(results, options.outPath);
   }
 
-  /** Array to collect all issues found during validation */
-  /** @type {Issue[]} */
-  const issues = [];
-
   /** Count of links ignored due to ignores configuration */
   let ignoredCount = 0;
 
@@ -771,11 +764,24 @@ export async function crawl(rawOptions) {
     }
   }
 
-  reportIssues(issues);
+  // Split issues by type for reporting
+  /** @type {BrokenLinkIssue[]} */
+  const brokenLinkIssues = /** @type {BrokenLinkIssue[]} */ (
+    issues.filter((issue) => issue.type === 'broken-link' || issue.type === 'broken-target')
+  );
+  /** @type {HtmlValidateIssue[]} */
+  const htmlValidateIssues = /** @type {HtmlValidateIssue[]} */ (
+    issues.filter((issue) => issue.type === 'html-validate')
+  );
+
+  reportBrokenLinks(brokenLinkIssues);
+  reportHtmlValidation(htmlValidateIssues);
 
   // Derive counts from issues
-  const brokenLinks = issues.filter((issue) => issue.type === 'broken-link').length;
-  const brokenLinkTargets = issues.filter((issue) => issue.type === 'broken-target').length;
+  const brokenLinks = brokenLinkIssues.filter((issue) => issue.type === 'broken-link').length;
+  const brokenLinkTargets = brokenLinkIssues.filter(
+    (issue) => issue.type === 'broken-target',
+  ).length;
 
   const endTime = Date.now();
   const durationSeconds = (endTime - startTime) / 1000;
@@ -784,14 +790,21 @@ export async function crawl(rawOptions) {
     unit: 'second',
     maximumFractionDigits: 2,
   }).format(durationSeconds);
+  const fmt = new Intl.NumberFormat('en-US').format;
   console.log(chalk.blue(`\nCrawl completed in ${duration}`));
-  console.log(`  Total links found: ${chalk.cyan(crawledLinks.size)}`);
-  console.log(`  Total broken links: ${chalk.cyan(brokenLinks)}`);
-  console.log(`  Total broken link targets: ${chalk.cyan(brokenLinkTargets)}`);
-  console.log(`  Total ignored: ${chalk.cyan(ignoredCount)}`);
+  console.log(`  Total links found: ${chalk.cyan(fmt(crawledLinks.size))}`);
+  console.log(`  Total broken links: ${chalk.cyan(fmt(brokenLinks))}`);
+  console.log(`  Total broken link targets: ${chalk.cyan(fmt(brokenLinkTargets))}`);
+  console.log(`  Total ignored: ${chalk.cyan(fmt(ignoredCount))}`);
+  if (options.htmlValidate) {
+    const pagesWithHtmlIssues = new Set(htmlValidateIssues.map((issue) => issue.pageUrl)).size;
+    console.log(
+      `  HTML validation issues: ${chalk.cyan(fmt(htmlValidateIssues.length))} across ${chalk.cyan(fmt(pagesWithHtmlIssues))} ${pagesWithHtmlIssues === 1 ? 'page' : 'pages'}`,
+    );
+  }
 
   if (options.outPath) {
-    console.log(chalk.blue(`Output written to: ${options.outPath}`));
+    console.log(chalk.blue(`Output written to: ${pathToFileURL(options.outPath)}`));
   }
 
   return { links: crawledLinks, pages: results, issues };
diff --git a/packages/code-infra/src/brokenLinksChecker/index.test.ts b/packages/code-infra/src/brokenLinksChecker/index.test.ts
index 025d30730..89e302c77 100644
--- a/packages/code-infra/src/brokenLinksChecker/index.test.ts
+++ b/packages/code-infra/src/brokenLinksChecker/index.test.ts
@@ -3,11 +3,11 @@ import getPort from 'get-port';
 import { describe, expect, it } from 'vitest';
 
 // eslint-disable-next-line import/extensions
-import { crawl, Issue, Link } from './index.mjs';
+import { crawl, BrokenLinkIssue, HtmlValidateIssue, Issue, Link } from './index.mjs';
 
-type ExpectedIssue = Omit<Partial<Issue>, 'link'> & { link?: Partial<Link> };
+type ExpectedBrokenLinkIssue = Omit<Partial<BrokenLinkIssue>, 'link'> & { link?: Partial<Link> };
 
-function objectMatchingIssue(expectedIssue: ExpectedIssue) {
+function objectMatchingIssue(expectedIssue: ExpectedBrokenLinkIssue) {
   return expect.objectContaining({
     ...expectedIssue,
     ...(expectedIssue.link ? { link: expect.objectContaining(expectedIssue.link) } : {}),
@@ -15,16 +15,16 @@ function objectMatchingIssue(expectedIssue: ExpectedIssue) {
 }
 
 /**
- * Helper to assert that an issue with matching properties exists in the issues array
+ * Helper to assert that a broken link issue with matching properties exists in the issues array
  */
-function expectIssue(issues: Issue[], expectedIssue: ExpectedIssue) {
+function expectIssue(issues: Issue[], expectedIssue: ExpectedBrokenLinkIssue) {
   expect(issues).toEqual(expect.arrayContaining([objectMatchingIssue(expectedIssue)]));
 }
 
 /**
- * Helper to assert that no issue with matching properties exists in the issues array
+ * Helper to assert that no broken link issue with matching properties exists in the issues array
  */
-function expectNotIssue(issues: Issue[], notExpectedIssue: ExpectedIssue) {
+function expectNotIssue(issues: Issue[], notExpectedIssue: ExpectedBrokenLinkIssue) {
   expect(issues).not.toEqual(expect.arrayContaining([objectMatchingIssue(notExpectedIssue)]));
 }
 
@@ -56,12 +56,21 @@ describe('Broken Links Checker', () => {
         // Test href-only rule (matches from any page) - note: matches the actual href value
         { href: 'broken-relative.html' },
       ],
+      htmlValidate: {
+        extends: ['mui:recommended'],
+        rules: {
+          'no-raw-characters': 'off',
+        },
+      },
     });
 
-    expect(result.links).toHaveLength(66);
-    // Issue count: original 11, minus ignored ones (broken-from-markdown via contentType,
+    expect(result.links).toHaveLength(67);
+    // Broken link issue count: original 11, minus ignored ones (broken-from-markdown via contentType,
     // broken-relative via href-only rule)
-    expect(result.issues).toHaveLength(9);
+    const brokenLinkIssues = result.issues.filter(
+      (issue) => issue.type === 'broken-link' || issue.type === 'broken-target',
+    );
+    expect(brokenLinkIssues).toHaveLength(9);
 
     // Test ignores: these broken links should be ignored (not in issues)
     expectNotIssue(result.issues, {
@@ -257,5 +266,32 @@ describe('Broken Links Checker', () => {
     // Test contentType is stored on pageData
     expect(result.pages.get('/example.md')?.contentType).toBe('text/markdown');
     expect(result.pages.get('/')?.contentType).toBe('text/html');
+
+    // Test htmlValidate: invalid-html.html has duplicate IDs which should be reported
+    const htmlValidateIssues = result.issues.filter(
+      (issue): issue is HtmlValidateIssue => issue.type === 'html-validate',
+    );
+    const invalidHtmlIssues = htmlValidateIssues.filter(
+      (issue) => issue.pageUrl === '/invalid-html.html',
+    );
+    expect(invalidHtmlIssues.length).toBeGreaterThan(0);
+    expect(invalidHtmlIssues).toEqual(
+      expect.arrayContaining([
+        expect.objectContaining({
+          type: 'html-validate',
+          pageUrl: '/invalid-html.html',
+          ruleId: 'no-dup-id',
+        }),
+      ]),
+    );
+
+    // Test htmlValidate override: no-raw-characters is off, so raw & should NOT be reported
+    expect(invalidHtmlIssues).not.toEqual(
+      expect.arrayContaining([
+        expect.objectContaining({
+          ruleId: 'no-raw-characters',
+        }),
+      ]),
+    );
   }, 30000);
 });
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 3b88d9ba9..31163a188 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -674,6 +674,9 @@ importers:
       globby:
         specifier: ^16.1.1
         version: 16.1.1
+      html-validate:
+        specifier: ^10.11.2
+        version: 10.11.2(jest-diff@30.2.0)(vitest@4.1.4(@opentelemetry/api@1.9.0)(@types/node@22.19.0)(@vitest/browser-playwright@4.1.1(playwright@1.58.2)(vite@8.0.5(@emnapi/core@1.9.0)(@emnapi/runtime@1.9.2)(@types/node@22.19.0)(esbuild@0.27.1)(jiti@2.6.1)(terser@5.44.0)(tsx@4.21.0)(yaml@2.8.1))(vitest@4.1.1))(@vitest/coverage-v8@4.1.2(vitest@4.1.1))(jsdom@28.1.0)(vite@8.0.5(@emnapi/core@1.9.0)(@emnapi/runtime@1.9.2)(@types/node@22.19.0)(esbuild@0.27.1)(jiti@2.6.1)(terser@5.44.0)(tsx@4.21.0)(yaml@2.8.1)))
       minimatch:
         specifier: ^10.2.4
         version: 10.2.5
@@ -2649,6 +2652,10 @@ packages:
     resolution: {integrity: sha512-bV8v7R/c0gNve8i7yPmZbcCTJUqRbCnMSvcegcMaz+ly+FoZf9i4+3MTjKsX+OZn9w0w1I6VJYQBcdM+yMWPQQ==}
     engines: {node: '>=0.10.0'}
 
+  '@html-validate/stylish@5.0.0':
+    resolution: {integrity: sha512-xjhRV9k1mWfgsOcpYlwsjUOFy3w3EnCDrqUrEw+DWdvOStMK59ts2H7GLKWZtmLI5m6Npp3qMSNReafQy9K2sA==}
+    engines: {node: ^20.11 || >= 22.16}
+
   '@humanfs/core@0.19.1':
     resolution: {integrity: sha512-5DyQ4+1JEUzejeK1JGICcideyfUbGixgS9jNgex5nqkW+cY7WZhxBigmieN5Qnw9ZosSNVC9KQKyb+GUaGyKUA==}
     engines: {node: '>=18.18.0'}
@@ -5523,6 +5530,12 @@ packages:
   '@sec-ant/readable-stream@0.4.1':
     resolution: {integrity: sha512-831qok9r2t8AlxLko40y2ebgSDhenenCatLVeW/uBtnHPyhHOvG0C7TvfgecV+wHzIm5KUICgzmVpWS+IMEAeg==}
 
+  '@sidvind/better-ajv-errors@4.0.1':
+    resolution: {integrity: sha512-6arF1ssKxItxgitPYXafUoLmsVBA6K7m9+ZGj6hLDoBl7nWpJ33EInwQUdHTle2METeWGxgQiqSex20KZRykew==}
+    engines: {node: '>= 18'}
+    peerDependencies:
+      ajv: ^7.0.0 || ^8.0.0
+
   '@sigstore/bundle@4.0.0':
     resolution: {integrity: sha512-NwCl5Y0V6Di0NexvkTqdoVfmjTaQwoLM236r89KEojGmq/jMls8S+zb7yOwAPdXvbwfKDlP+lmXgAL4vKSQT+A==}
     engines: {node: ^20.17.0 || >=22.9.0}
@@ -8876,6 +8889,25 @@ packages:
     resolution: {integrity: sha512-QY6S+hZ0f5m1WT8WffYN+Hg+xm/w5I8XeUcAq/ZYP5wVC8xbKi4Whhru3FtrAebD5EhBW8rmFzkDI6eCAuFe2w==}
     hasBin: true
 
+  html-validate@10.11.2:
+    resolution: {integrity: sha512-ZT4812sBvF77WrfTNWcaaml7xSOMDsGvw3plP4zrgcPw5RWESsRgprsVVYnaQD2lSNfD0WObZ0Ur22+xXj0TXA==}
+    engines: {node: ^20.19.0 || >= 22.16.0}
+    hasBin: true
+    peerDependencies:
+      jest: ^28.1.3 || ^29.0.3 || ^30.0.0
+      jest-diff: ^28.1.3 || ^29.0.3 || ^30.0.0
+      jest-snapshot: ^28.1.3 || ^29.0.3 || ^30.0.0
+      vitest: ^1.0.0 || ^2.0.0 || ^3.0.0 || ^4.0.1
+    peerDependenciesMeta:
+      jest:
+        optional: true
+      jest-diff:
+        optional: true
+      jest-snapshot:
+        optional: true
+      vitest:
+        optional: true
+
   html-void-elements@3.0.0:
     resolution: {integrity: sha512-bEqo66MRXsUGxWHV5IP0PUiAWwoEjba4VCzg0LjFJBpchPaTfyfCKTG6bc5F8ucKec3q5y6qOdGyYTSBEvhCrg==}
 
@@ -9487,6 +9519,10 @@ packages:
     resolution: {integrity: sha512-eTIzlVOSUR+JxdDFepEYcBMtZ9Qqdef+rnzWdRZuMbOywu5tO2w2N7rqjoANZ5k9vywhL6Br1VRjUIgTQx4E8w==}
     engines: {node: '>=6'}
 
+  kleur@4.1.5:
+    resolution: {integrity: sha512-o+NO+8WrRiQEE4/7nwRJhN1HWpVmJm511pBHUxPLtp0BUISzlBplORYSmTclCnJvQq2tKu/sgl3xVpkc7ZWuQQ==}
+    engines: {node: '>=6'}
+
   ky@1.14.0:
     resolution: {integrity: sha512-Rczb6FMM6JT0lvrOlP5WUOCB7s9XKxzwgErzhKlKde1bEV90FXplV1o87fpt4PU/asJFiqjYJxAJyzJhcrxOsQ==}
     engines: {node: '>=18'}
@@ -14864,6 +14900,10 @@ snapshots:
     dependencies:
       ip-address: 5.9.4
 
+  '@html-validate/stylish@5.0.0':
+    dependencies:
+      kleur: 4.1.5
+
   '@humanfs/core@0.19.1': {}
 
   '@humanfs/node@0.16.7':
@@ -17918,6 +17958,11 @@ snapshots:
 
   '@sec-ant/readable-stream@0.4.1': {}
 
+  '@sidvind/better-ajv-errors@4.0.1(ajv@8.18.0)':
+    dependencies:
+      ajv: 8.18.0
+      kleur: 4.1.5
+
   '@sigstore/bundle@4.0.0':
     dependencies:
       '@sigstore/protobuf-specs': 0.5.0
@@ -22325,6 +22370,20 @@ snapshots:
       readable-stream: 1.0.34
       through2: 0.4.2
 
+  html-validate@10.11.2(jest-diff@30.2.0)(vitest@4.1.4(@opentelemetry/api@1.9.0)(@types/node@22.19.0)(@vitest/browser-playwright@4.1.1(playwright@1.58.2)(vite@8.0.5(@emnapi/core@1.9.0)(@emnapi/runtime@1.9.2)(@types/node@22.19.0)(esbuild@0.27.1)(jiti@2.6.1)(terser@5.44.0)(tsx@4.21.0)(yaml@2.8.1))(vitest@4.1.1))(@vitest/coverage-v8@4.1.2(vitest@4.1.1))(jsdom@28.1.0)(vite@8.0.5(@emnapi/core@1.9.0)(@emnapi/runtime@1.9.2)(@types/node@22.19.0)(esbuild@0.27.1)(jiti@2.6.1)(terser@5.44.0)(tsx@4.21.0)(yaml@2.8.1))):
+    dependencies:
+      '@html-validate/stylish': 5.0.0
+      '@sidvind/better-ajv-errors': 4.0.1(ajv@8.18.0)
+      ajv: 8.18.0
+      glob: 13.0.6
+      kleur: 4.1.5
+      minimist: 1.2.8
+      prompts: 2.4.2
+      semver: 7.7.4
+    optionalDependencies:
+      jest-diff: 30.2.0
+      vitest: 4.1.4(@opentelemetry/api@1.9.0)(@types/node@22.19.0)(@vitest/browser-playwright@4.1.1(playwright@1.58.2)(vite@8.0.5(@emnapi/core@1.9.0)(@emnapi/runtime@1.9.2)(@types/node@22.19.0)(esbuild@0.27.1)(jiti@2.6.1)(terser@5.44.0)(tsx@4.21.0)(yaml@2.8.1))(vitest@4.1.1))(@vitest/coverage-v8@4.1.2(vitest@4.1.1))(jsdom@28.1.0)(vite@8.0.5(@emnapi/core@1.9.0)(@emnapi/runtime@1.9.2)(@types/node@22.19.0)(esbuild@0.27.1)(jiti@2.6.1)(terser@5.44.0)(tsx@4.21.0)(yaml@2.8.1))
+
   html-void-elements@3.0.0: {}
 
   http-cache-semantics@4.2.0: {}
@@ -22915,6 +22974,8 @@ snapshots:
 
   kleur@3.0.3: {}
 
+  kleur@4.1.5: {}
+
   ky@1.14.0: {}
 
   language-subtag-registry@0.3.23: {}