feat(render): highlight quill code blocks with language

src/assets/markdown-override.css

@@ -66,8 +66,20 @@
 }
 
 .markdown-body .ql-code-block {
-  white-space: pre-wrap;
-  word-break: break-word;
+  white-space: pre;
+  word-break: normal;
+  overflow-x: auto;
+}
+
+/* Markdown code blocks: horizontal scroll, no wrapping */
+.markdown-body pre {
+  overflow-x: auto;
+}
+
+.markdown-body pre code {
+  white-space: pre;
+  word-break: normal;
+  overflow-x: auto;
 }
 
 .markdown-body.markdown-body-dark .ql-code-block-container {

src/utils/markdown.ts

@@ -16,9 +16,42 @@ marked.use(
   })
 )
 
+function highlightHtmlCode(html: string): string {
+  const doc = new DOMParser().parseFromString(html, 'text/html')
+  const blocks = Array.from(doc.querySelectorAll<HTMLElement>('pre'))
+  for (const pre of blocks) {
+    const container = pre.closest<HTMLElement>('.ql-code-block-container')
+    const codeEl = pre.querySelector<HTMLElement>('code')
+    let lang = container?.getAttribute('data-language') ?? ''
+    if (!lang && codeEl) {
+      const m = (codeEl.className || '').match(/language-([\w-]+)/)
+      if (m) lang = m[1]
+    }
+    const text = codeEl ? codeEl.textContent ?? '' : pre.textContent ?? ''
+    let highlighted: string
+    if (lang && hljs.getLanguage(lang)) {
+      highlighted = hljs.highlight(text, { language: lang }).value
+    } else {
+      highlighted = hljs.highlightAuto(text).value
+    }
+    if (codeEl) {
+      codeEl.innerHTML = highlighted
+      codeEl.classList.add('hljs')
+    } else {
+      const newCode = doc.createElement('code')
+      newCode.className = 'hljs'
+      newCode.innerHTML = highlighted
+      pre.innerHTML = ''
+      pre.appendChild(newCode)
+    }
+  }
+  return doc.body.innerHTML
+}
+
 export function renderArticle(content: string): string {
   if (content.trimStart().startsWith('<')) {
-    return DOMPurify.sanitize(content)
+    const safe = DOMPurify.sanitize(content)
+    return highlightHtmlCode(safe)
   }
   const rawHtml = marked.parse(content, { async: false }) as string
   return DOMPurify.sanitize(rawHtml)