feat(docs): in-app docs viewer at /docs

Renders every file in docs/*.md as a proper documentation site styled
like Stripe / Vercel / Linear docs: sticky header, grouped left sidebar
(Setup / Deploy / Operate), dark prose with inline code pills, syntax
-ready code blocks, responsive table styling, and prev/next pagination.

- src/lib/docs/content.ts — parses md with marked and decorates the
  HTML with Tailwind utility classes via post-processing regex. Also
  rewrites inter-doc `./other.md` links to `/docs/other` and extracts
  an h2/h3 TOC for future use.
- src/app/docs/layout.tsx + src/components/docs/shell.tsx — shared
  frame with docs-scoped header (GitHub, Home, Get started), collapsing
  sidebar on mobile.
- src/app/docs/page.tsx — grouped index cards per section.
- src/app/docs/[slug]/page.tsx — individual doc + prev/next nav.
- Adds "Docs" to landing nav, footer, and a "Read the full
  documentation" CTA under the open-source cards.
- Adds `marked` dependency.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

package-lock.json

@@ -18,6 +18,7 @@
         "clsx": "^2.1.1",
         "date-fns": "^4.1.0",
         "lucide-react": "^1.8.0",
+        "marked": "^18.0.2",
         "next": "16.2.4",
         "react": "19.2.4",
         "react-dom": "19.2.4",
@@ -7018,6 +7019,18 @@
         "@jridgewell/sourcemap-codec": "^1.5.5"
       }
     },
+    "node_modules/marked": {
+      "version": "18.0.2",
+      "resolved": "https://registry.npmjs.org/marked/-/marked-18.0.2.tgz",
+      "integrity": "sha512-NsmlUYBS/Zg57rgDWMYdnre6OTj4e+qq/JS2ot3KrYLSoHLw+sDu0Nm1ZGpRgYAq6c+b1ekaY5NzVchMCQnzcg==",
+      "license": "MIT",
+      "bin": {
+        "marked": "bin/marked.js"
+      },
+      "engines": {
+        "node": ">= 20"
+      }
+    },
     "node_modules/math-intrinsics": {
       "version": "1.1.0",
       "resolved": "https://registry.npmjs.org/math-intrinsics/-/math-intrinsics-1.1.0.tgz",

package.json

@@ -19,6 +19,7 @@
     "clsx": "^2.1.1",
     "date-fns": "^4.1.0",
     "lucide-react": "^1.8.0",
+    "marked": "^18.0.2",
     "next": "16.2.4",
     "react": "19.2.4",
     "react-dom": "19.2.4",

src/app/docs/[slug]/page.tsx

@@ -0,0 +1,87 @@
+import type { Metadata } from 'next'
+import { notFound } from 'next/navigation'
+import Link from 'next/link'
+import { ArrowLeft, ArrowRight } from 'lucide-react'
+import { listDocs, loadDoc } from '@/lib/docs/content'
+
+interface DocPageProps {
+  params: Promise<{ slug: string }>
+}
+
+export async function generateStaticParams() {
+  const pages = await listDocs()
+  return pages.map((p) => ({ slug: p.slug }))
+}
+
+export async function generateMetadata({
+  params,
+}: DocPageProps): Promise<Metadata> {
+  const { slug } = await params
+  const doc = await loadDoc(slug)
+  if (!doc) return {}
+  return {
+    title: doc.title,
+    description: doc.description,
+  }
+}
+
+export default async function DocPage({ params }: DocPageProps) {
+  const { slug } = await params
+  const doc = await loadDoc(slug)
+  if (!doc) notFound()
+
+  const pages = await listDocs()
+  const idx = pages.findIndex((p) => p.slug === slug)
+  const prev = idx > 0 ? pages[idx - 1] : null
+  const next = idx >= 0 && idx < pages.length - 1 ? pages[idx + 1] : null
+
+  return (
+    <article className="mx-auto w-full max-w-3xl">
+      <p className="text-xs font-semibold uppercase tracking-wider text-emerald-400">
+        {doc.section}
+      </p>
+      <div
+        className="doc-prose mt-2"
+        dangerouslySetInnerHTML={{ __html: doc.html }}
+      />
+
+      <nav
+        aria-label="Pagination"
+        className="mt-16 grid grid-cols-1 gap-3 border-t border-slate-800 pt-8 sm:grid-cols-2"
+      >
+        {prev ? (
+          <Link
+            href={`/docs/${prev.slug}`}
+            className="group flex flex-col gap-1 rounded-xl border border-slate-800 bg-slate-900/40 px-5 py-4 transition-colors hover:border-slate-700 hover:bg-slate-900/70"
+          >
+            <span className="inline-flex items-center gap-1.5 text-xs font-semibold uppercase tracking-wider text-slate-500">
+              <ArrowLeft className="h-3.5 w-3.5" />
+              Previous
+            </span>
+            <span className="text-sm font-semibold text-white">
+              {prev.title}
+            </span>
+          </Link>
+        ) : (
+          <span />
+        )}
+        {next ? (
+          <Link
+            href={`/docs/${next.slug}`}
+            className="group flex flex-col items-end gap-1 rounded-xl border border-slate-800 bg-slate-900/40 px-5 py-4 text-right transition-colors hover:border-slate-700 hover:bg-slate-900/70"
+          >
+            <span className="inline-flex items-center gap-1.5 text-xs font-semibold uppercase tracking-wider text-slate-500">
+              Next
+              <ArrowRight className="h-3.5 w-3.5" />
+            </span>
+            <span className="text-sm font-semibold text-white">
+              {next.title}
+            </span>
+          </Link>
+        ) : (
+          <span />
+        )}
+      </nav>
+    </article>
+  )
+}

src/app/docs/layout.tsx

@@ -0,0 +1,18 @@
+import type { Metadata } from 'next'
+import { DocsShell } from '@/components/docs/shell'
+import { listDocs } from '@/lib/docs/content'
+
+export const metadata: Metadata = {
+  title: { template: '%s — WaCRM Docs', default: 'WaCRM Docs' },
+  description:
+    'Setup, configuration, and deployment docs for the WaCRM template.',
+}
+
+export default async function DocsLayout({
+  children,
+}: {
+  children: React.ReactNode
+}) {
+  const pages = await listDocs()
+  return <DocsShell pages={pages}>{children}</DocsShell>
+}

src/app/docs/page.tsx

@@ -0,0 +1,60 @@
+import Link from 'next/link'
+import { ArrowRight } from 'lucide-react'
+import { listDocs } from '@/lib/docs/content'
+
+export default async function DocsIndexPage() {
+  const pages = await listDocs()
+  const sections: Record<string, typeof pages> = {}
+  for (const p of pages) {
+    sections[p.section] ??= []
+    sections[p.section].push(p)
+  }
+
+  return (
+    <article className="mx-auto w-full max-w-3xl">
+      <p className="text-xs font-semibold uppercase tracking-wider text-emerald-400">
+        Documentation
+      </p>
+      <h1 className="mt-2 text-3xl font-bold tracking-tight text-white sm:text-4xl">
+        Self-host WaCRM end to end
+      </h1>
+      <p className="mt-4 text-base leading-relaxed text-slate-400">
+        Everything you need to take the template from a fresh fork to a
+        production deploy. Work through the pages in order, or jump to the
+        one you need.
+      </p>
+
+      <div className="mt-10 flex flex-col gap-10">
+        {Object.entries(sections).map(([section, items]) => (
+          <section key={section}>
+            <h2 className="text-xs font-semibold uppercase tracking-wider text-slate-500">
+              {section}
+            </h2>
+            <div className="mt-4 grid grid-cols-1 gap-3 sm:grid-cols-2">
+              {items.map((p) => (
+                <Link
+                  key={p.slug}
+                  href={`/docs/${p.slug}`}
+                  className="group flex flex-col rounded-xl border border-slate-800 bg-slate-900/40 p-5 transition-colors hover:border-slate-700 hover:bg-slate-900/70"
+                >
+                  <h3 className="text-sm font-semibold text-white">
+                    {p.title}
+                  </h3>
+                  {p.description && (
+                    <p className="mt-1.5 text-sm leading-relaxed text-slate-400">
+                      {p.description}
+                    </p>
+                  )}
+                  <span className="mt-4 inline-flex items-center gap-1.5 text-xs font-medium text-emerald-400 transition-colors group-hover:text-emerald-300">
+                    Read
+                    <ArrowRight className="h-3.5 w-3.5 transition-transform group-hover:translate-x-0.5" />
+                  </span>
+                </Link>
+              ))}
+            </div>
+          </section>
+        ))}
+      </div>
+    </article>
+  )
+}

src/components/docs/shell.tsx

@@ -0,0 +1,94 @@
+"use client"
+
+import { useState, type ReactNode } from 'react'
+import Link from 'next/link'
+import { Menu, X } from 'lucide-react'
+import { DocsSidebar } from './sidebar'
+import { GithubIcon } from '@/components/landing/github-icon'
+import { MessageSquare } from 'lucide-react'
+import type { DocPage } from '@/lib/docs/content'
+
+const REPO_URL = 'https://github.com/ArnasDon/wacrm'
+
+interface DocsShellProps {
+  pages: DocPage[]
+  children: ReactNode
+}
+
+export function DocsShell({ pages, children }: DocsShellProps) {
+  const [mobileOpen, setMobileOpen] = useState(false)
+  const closeMobile = () => setMobileOpen(false)
+
+  return (
+    <div className="min-h-screen bg-slate-950 text-slate-100">
+      <header className="sticky top-0 z-40 border-b border-slate-800 bg-slate-950/80 backdrop-blur">
+        <div className="mx-auto flex h-16 w-full max-w-7xl items-center justify-between gap-4 px-4 sm:px-6">
+          <div className="flex items-center gap-2">
+            <button
+              type="button"
+              className="flex h-9 w-9 items-center justify-center rounded-lg text-slate-300 transition-colors hover:bg-slate-800 hover:text-white lg:hidden"
+              aria-label={mobileOpen ? 'Close docs menu' : 'Open docs menu'}
+              onClick={() => setMobileOpen((v) => !v)}
+            >
+              {mobileOpen ? <X className="h-5 w-5" /> : <Menu className="h-5 w-5" />}
+            </button>
+            <Link href="/" className="flex items-center gap-2" aria-label="WaCRM home">
+              <span className="flex h-8 w-8 items-center justify-center rounded-lg bg-emerald-500">
+                <MessageSquare className="h-4 w-4 text-white" />
+              </span>
+              <span className="text-lg font-semibold text-white">WaCRM</span>
+              <span className="hidden rounded-md border border-slate-700 bg-slate-900 px-1.5 py-0.5 text-[10px] font-semibold uppercase tracking-wider text-slate-400 sm:inline-block">
+                Docs
+              </span>
+            </Link>
+          </div>
+
+          <div className="flex items-center gap-1.5">
+            <Link
+              href="/"
+              className="hidden rounded-lg px-3 py-1.5 text-sm text-slate-300 transition-colors hover:bg-slate-800 hover:text-white sm:inline-flex"
+            >
+              Home
+            </Link>
+            <a
+              href={REPO_URL}
+              target="_blank"
+              rel="noopener noreferrer"
+              aria-label="View source on GitHub"
+              className="flex h-9 w-9 items-center justify-center rounded-lg text-slate-300 transition-colors hover:bg-slate-800 hover:text-white"
+            >
+              <GithubIcon className="h-4 w-4" />
+            </a>
+            <Link
+              href="/signup"
+              className="inline-flex items-center justify-center rounded-lg bg-emerald-500 px-3 py-1.5 text-sm font-medium text-white transition-colors hover:bg-emerald-400"
+            >
+              Get started
+            </Link>
+          </div>
+        </div>
+      </header>
+
+      <div className="mx-auto flex w-full max-w-7xl gap-8 px-4 sm:px-6">
+        <aside className="sticky top-16 hidden h-[calc(100vh-4rem)] w-64 flex-shrink-0 overflow-y-auto py-10 pr-2 lg:block">
+          <DocsSidebar pages={pages} />
+        </aside>
+
+        {mobileOpen && (
+          <div className="fixed inset-0 top-16 z-30 flex lg:hidden">
+            <div
+              className="absolute inset-0 bg-slate-950/80 backdrop-blur-sm"
+              onClick={closeMobile}
+              aria-hidden
+            />
+            <div className="relative ml-0 mr-auto flex h-full w-72 max-w-[85vw] flex-col overflow-y-auto border-r border-slate-800 bg-slate-950 px-4 py-6">
+              <DocsSidebar pages={pages} onNavigate={closeMobile} />
+            </div>
+          </div>
+        )}
+
+        <main className="min-w-0 flex-1 py-10">{children}</main>
+      </div>
+    </div>
+  )
+}

src/components/docs/sidebar.tsx

@@ -0,0 +1,68 @@
+"use client"
+
+import Link from 'next/link'
+import { usePathname } from 'next/navigation'
+import { cn } from '@/lib/utils'
+import type { DocPage } from '@/lib/docs/content'
+
+interface DocsSidebarProps {
+  pages: DocPage[]
+  onNavigate?: () => void
+}
+
+export function DocsSidebar({ pages, onNavigate }: DocsSidebarProps) {
+  const pathname = usePathname()
+
+  const sections: Record<string, DocPage[]> = {}
+  for (const p of pages) {
+    sections[p.section] ??= []
+    sections[p.section].push(p)
+  }
+
+  return (
+    <nav aria-label="Documentation" className="flex flex-col gap-6 text-sm">
+      <Link
+        href="/docs"
+        onClick={onNavigate}
+        className={cn(
+          'flex items-center justify-between rounded-md px-3 py-2 transition-colors',
+          pathname === '/docs'
+            ? 'bg-slate-800 text-white'
+            : 'text-slate-300 hover:bg-slate-800/60 hover:text-white',
+        )}
+      >
+        <span>Overview</span>
+      </Link>
+
+      {Object.entries(sections).map(([section, items]) => (
+        <div key={section}>
+          <p className="mb-2 px-3 text-[10px] font-semibold uppercase tracking-wider text-slate-500">
+            {section}
+          </p>
+          <ul className="flex flex-col gap-0.5">
+            {items.map((p) => {
+              const href = `/docs/${p.slug}`
+              const active = pathname === href
+              return (
+                <li key={p.slug}>
+                  <Link
+                    href={href}
+                    onClick={onNavigate}
+                    className={cn(
+                      'block rounded-md px-3 py-1.5 transition-colors',
+                      active
+                        ? 'bg-emerald-500/10 text-emerald-300'
+                        : 'text-slate-400 hover:bg-slate-800/60 hover:text-white',
+                    )}
+                  >
+                    {p.title}
+                  </Link>
+                </li>
+              )
+            })}
+          </ul>
+        </div>
+      ))}
+    </nav>
+  )
+}

src/components/landing/footer.tsx

@@ -37,6 +37,7 @@ export function Footer() {
               external: true,
             },
             { href: '#self-host', label: 'Self-host' },
+            { href: '/docs', label: 'Docs' },
             {
               href: 'https://www.hostinger.com/web-apps-hosting',
               label: 'Deploy on Hostinger',

src/components/landing/nav.tsx

@@ -19,6 +19,7 @@ const LINKS = [
   { href: '#features', label: 'Features' },
   { href: '#how-it-works', label: 'How it works' },
   { href: '#self-host', label: 'Self-host' },
+  { href: '/docs', label: 'Docs' },
   { href: '#faq', label: 'FAQ' },
 ]
 

src/components/landing/open-source.tsx

@@ -1,4 +1,5 @@
-import { ArrowRight, Server } from 'lucide-react'
+import Link from 'next/link'
+import { ArrowRight, BookOpen, Server } from 'lucide-react'
 import { Section, SectionHeader } from './section'
 import { GithubIcon } from './github-icon'
 
@@ -63,6 +64,17 @@ export function OpenSource() {
           </span>
         </a>
       </div>
+
+      <div className="mx-auto mt-6 flex max-w-5xl items-center justify-center">
+        <Link
+          href="/docs"
+          className="group inline-flex items-center gap-2 rounded-lg border border-slate-800 bg-slate-900/40 px-5 py-3 text-sm font-medium text-slate-200 transition-colors hover:border-slate-700 hover:bg-slate-900/70 hover:text-white"
+        >
+          <BookOpen className="h-4 w-4 text-emerald-400" />
+          Read the full documentation
+          <ArrowRight className="h-4 w-4 text-slate-400 transition-transform group-hover:translate-x-0.5 group-hover:text-slate-200" />
+        </Link>
+      </div>
     </Section>
   )
 }

src/lib/docs/content.ts

@@ -0,0 +1,222 @@
+import { promises as fs } from 'node:fs'
+import path from 'node:path'
+import { marked } from 'marked'
+
+const DOCS_DIR = path.join(process.cwd(), 'docs')
+
+export interface DocPage {
+  slug: string
+  title: string
+  description?: string
+  order: number
+  section: string
+}
+
+export interface DocContent extends DocPage {
+  html: string
+  toc: Array<{ id: string; text: string; depth: number }>
+}
+
+// Hand-curated because file order on disk is not reading order.
+const ORDER: Record<string, { order: number; section: string; description: string }> = {
+  'getting-started': {
+    order: 1,
+    section: 'Setup',
+    description: 'Fork, install, run WaCRM locally in about 15 minutes.',
+  },
+  'supabase-setup': {
+    order: 2,
+    section: 'Setup',
+    description: 'Create the database, apply migrations, grab the keys.',
+  },
+  'whatsapp-setup': {
+    order: 3,
+    section: 'Setup',
+    description: 'Meta app, access token, webhook verification.',
+  },
+  'environment-variables': {
+    order: 4,
+    section: 'Setup',
+    description: 'Full reference for every env var WaCRM reads.',
+  },
+  'deployment-hostinger': {
+    order: 5,
+    section: 'Deploy',
+    description: 'Ship WaCRM on Hostinger Managed Node.js Hosting.',
+  },
+  'automations-and-cron': {
+    order: 6,
+    section: 'Deploy',
+    description: 'Schedule the drain so Wait steps resume on time.',
+  },
+  troubleshooting: {
+    order: 7,
+    section: 'Operate',
+    description: 'The usual suspects when something breaks.',
+  },
+}
+
+// Tailwind classes applied after marked renders.
+// Listed as full class strings so Tailwind's source scanner picks them up.
+const CLASSES = {
+  h1: 'text-3xl sm:text-4xl font-bold tracking-tight text-white mt-1 mb-4 scroll-mt-20',
+  h2: 'text-2xl font-semibold tracking-tight text-white mt-10 mb-3 pt-6 border-t border-slate-800 scroll-mt-20',
+  h3: 'text-lg font-semibold text-white mt-8 mb-2 scroll-mt-20',
+  p: 'my-3 text-slate-300 leading-relaxed',
+  ul: 'my-3 pl-6 list-disc marker:text-slate-500 text-slate-300 leading-relaxed space-y-1.5',
+  ol: 'my-3 pl-6 list-decimal marker:text-slate-500 text-slate-300 leading-relaxed space-y-1.5',
+  li: 'pl-1',
+  blockquote: 'my-4 rounded-r-lg border-l-4 border-emerald-500 bg-emerald-500/5 px-4 py-3 text-slate-200',
+  hr: 'my-8 border-t border-slate-800',
+  a: 'text-emerald-400 underline decoration-transparent underline-offset-2 transition-colors hover:decoration-emerald-500/60',
+  codespan: 'rounded-md border border-slate-700 bg-slate-800 px-1.5 py-0.5 text-[0.85em] font-mono text-slate-100',
+  pre: 'my-5 overflow-x-auto rounded-lg border border-slate-800 bg-slate-900/80 p-4 text-[0.825rem] leading-relaxed font-mono text-slate-100',
+  table: 'my-5 block w-full overflow-x-auto rounded-lg border border-slate-800 text-sm',
+  th: 'border-b border-slate-800 px-3.5 py-2.5 text-left text-xs font-semibold uppercase tracking-wide text-white bg-slate-900/60',
+  td: 'border-b border-slate-800 px-3.5 py-2.5 text-left align-top text-slate-300',
+  strong: 'font-semibold text-white',
+}
+
+let pagesCache: DocPage[] | null = null
+
+export async function listDocs(): Promise<DocPage[]> {
+  if (pagesCache) return pagesCache
+  const entries = await fs.readdir(DOCS_DIR)
+  const pages: DocPage[] = []
+  for (const file of entries) {
+    if (!file.endsWith('.md') || file === 'README.md') continue
+    const slug = file.replace(/\.md$/, '')
+    const meta = ORDER[slug]
+    if (!meta) continue
+    const raw = await fs.readFile(path.join(DOCS_DIR, file), 'utf8')
+    const title = extractTitle(raw) ?? slug
+    pages.push({
+      slug,
+      title,
+      description: meta.description,
+      order: meta.order,
+      section: meta.section,
+    })
+  }
+  pages.sort((a, b) => a.order - b.order)
+  pagesCache = pages
+  return pages
+}
+
+export async function loadDoc(slug: string): Promise<DocContent | null> {
+  const pages = await listDocs()
+  const meta = pages.find((p) => p.slug === slug)
+  if (!meta) return null
+  const raw = await fs.readFile(path.join(DOCS_DIR, `${slug}.md`), 'utf8')
+
+  // Resolve inter-doc links like `./supabase-setup.md` to `/docs/supabase-setup`.
+  const rewritten = raw.replace(
+    /\]\(\.\/([a-zA-Z0-9-_]+)\.md([^)]*)\)/g,
+    (_, target: string, rest: string) => `](/docs/${target}${rest})`,
+  )
+
+  const vanilla = await marked.parse(rewritten, { gfm: true, breaks: false })
+  const { html, toc } = decorate(vanilla as string)
+
+  return { ...meta, html, toc }
+}
+
+function decorate(html: string): { html: string; toc: DocContent['toc'] } {
+  const toc: DocContent['toc'] = []
+
+  let out = html
+
+  // Headings: add id + Tailwind classes. Collect h2/h3 for TOC.
+  out = out.replace(
+    /<h([1-6])>([\s\S]*?)<\/h\1>/g,
+    (_, depthStr: string, inner: string) => {
+      const depth = Number(depthStr)
+      const text = stripTags(inner)
+      const id = slugify(text)
+      if (depth >= 2 && depth <= 3) toc.push({ id, text, depth })
+      const cls =
+        depth === 1
+          ? CLASSES.h1
+          : depth === 2
+            ? CLASSES.h2
+            : depth === 3
+              ? CLASSES.h3
+              : ''
+      return `<h${depth} id="${id}" class="${cls}">${inner}</h${depth}>`
+    },
+  )
+
+  // Drop the top border from the very first h2 so it doesn't read as a
+  // divider right under the page title.
+  let firstH2 = true
+  out = out.replace(
+    /<h2 (id="[^"]*") class="([^"]*)"/g,
+    (match, idAttr: string, cls: string) => {
+      if (!firstH2) return match
+      firstH2 = false
+      const trimmed = cls
+        .replace(/(?:^|\s)border-t(?:\s|$)/, ' ')
+        .replace(/(?:^|\s)border-slate-800(?:\s|$)/, ' ')
+        .replace(/(?:^|\s)pt-6(?:\s|$)/, ' ')
+        .replace(/(?:^|\s)mt-10(?:\s|$)/, ' mt-6 ')
+        .trim()
+        .replace(/\s+/g, ' ')
+      return `<h2 ${idAttr} class="${trimmed}"`
+    },
+  )
+
+  out = out.replace(/<p>/g, `<p class="${CLASSES.p}">`)
+  out = out.replace(/<ul>/g, `<ul class="${CLASSES.ul}">`)
+  out = out.replace(/<ol>/g, `<ol class="${CLASSES.ol}">`)
+  out = out.replace(/<li>/g, `<li class="${CLASSES.li}">`)
+  out = out.replace(/<blockquote>/g, `<blockquote class="${CLASSES.blockquote}">`)
+  out = out.replace(/<hr>/g, `<hr class="${CLASSES.hr}" />`)
+  out = out.replace(/<strong>/g, `<strong class="${CLASSES.strong}">`)
+  out = out.replace(/<table>/g, `<table class="${CLASSES.table}">`)
+  out = out.replace(/<th>/g, `<th class="${CLASSES.th}">`)
+  out = out.replace(/<th align="([^"]+)">/g, `<th align="$1" class="${CLASSES.th}">`)
+  out = out.replace(/<td>/g, `<td class="${CLASSES.td}">`)
+  out = out.replace(/<td align="([^"]+)">/g, `<td align="$1" class="${CLASSES.td}">`)
+
+  // Inline <code> from marked comes wrapped in <pre> for code blocks, or
+  // bare for codespan. We distinguish by whether <pre> precedes it.
+  out = out.replace(
+    /<pre><code( class="language-[^"]*")?>/g,
+    (_, langAttr = '') =>
+      `<pre class="${CLASSES.pre}"><code${langAttr}>`,
+  )
+  // Remaining <code> tags are inline codespans.
+  out = out.replace(
+    /<code(?! class="language-)([^>]*)>/g,
+    (_, rest: string) => `<code${rest} class="${CLASSES.codespan}">`,
+  )
+
+  // Links: style + open http(s) in new tabs.
+  out = out.replace(
+    /<a href="([^"]+)"([^>]*)>/g,
+    (_, href: string, rest: string) => {
+      const isExternal = /^https?:\/\//i.test(href)
+      const extra = isExternal ? ' target="_blank" rel="noopener noreferrer"' : ''
+      return `<a href="${href}"${rest} class="${CLASSES.a}"${extra}>`
+    },
+  )
+
+  return { html: out, toc }
+}
+
+function extractTitle(raw: string): string | null {
+  const match = raw.match(/^#\s+(.+?)\s*$/m)
+  return match ? match[1].trim() : null
+}
+
+function stripTags(input: string): string {
+  return input.replace(/<[^>]*>/g, '').trim()
+}
+
+function slugify(input: string): string {
+  return input
+    .toLowerCase()
+    .replace(/[^a-z0-9\s-]/g, '')
+    .trim()
+    .replace(/\s+/g, '-')
+}