diff --git a/apps/web/src/components/mobile-menu.tsx b/apps/web/src/components/mobile-menu.tsx
new file mode 100644
index 00000000..6665e23e
--- /dev/null
+++ b/apps/web/src/components/mobile-menu.tsx
@@ -0,0 +1,40 @@
+'use client'
+
+import { type ReactNode, useEffect, useRef } from 'react'
+
+export function MobileMenu({ children }: { readonly children: ReactNode }) {
+  const details = useRef<HTMLDetailsElement>(null)
+
+  useEffect(() => {
+    function onKey(event: KeyboardEvent) {
+      if (event.key === 'Escape' && details.current?.open) {
+        details.current.open = false
+        details.current.querySelector('summary')?.focus()
+      }
+    }
+    document.addEventListener('keydown', onKey)
+    return () => document.removeEventListener('keydown', onKey)
+  }, [])
+
+  return (
+    <details className="mobile-menu md:hidden" ref={details}>
+      <summary aria-label="Menu" className="mobile-menu-button">
+        <span aria-hidden className="mobile-menu-bars">
+          <span />
+          <span />
+          <span />
+        </span>
+      </summary>
+      <div
+        className="mobile-menu-panel"
+        onClickCapture={(event) => {
+          if (event.target instanceof Element && event.target.closest('a') && details.current) {
+            details.current.open = false
+          }
+        }}
+      >
+        {children}
+      </div>
+    </details>
+  )
+}
diff --git a/apps/web/src/components/site-header.tsx b/apps/web/src/components/site-header.tsx
index 936bfb78..2d11824c 100644
--- a/apps/web/src/components/site-header.tsx
+++ b/apps/web/src/components/site-header.tsx
@@ -7,11 +7,14 @@ import { quickstartHref } from '../docs/registry'
 import { DemoLink } from './demo-link'
 import { DocsSearch } from './docs-search'
 import { Logomark } from './logomark'
+import { MobileMenu } from './mobile-menu'
 import { ThemeToggle } from './theme-toggle'
 
 const item = 'text-micro font-medium text-fg-muted transition-colors hover:text-fg'
 
 export function SiteHeader() {
+  const startHref = quickstartHref()
+
   return (
     <header className="sticky top-0 z-40 border-b border-border bg-canvas/85 backdrop-blur-lg">
       <div aria-hidden className="top-beam" />
@@ -26,7 +29,7 @@ export function SiteHeader() {
             Product
           </Link>
 
-          <div className="menu hidden sm:block">
+          <div className="menu hidden md:block">
             <Link href={audienceIndexHref} className={`${item} inline-flex items-center gap-1`}>
               Who it&rsquo;s for
               <span aria-hidden className="menu-caret">
@@ -49,24 +52,72 @@ export function SiteHeader() {
             </ul>
           </div>
 
-          <Link href="/docs" className={item}>
+          <Link href="/docs" className={`hidden ${item} md:inline`}>
             Docs
           </Link>
-          <DemoLink className={item}>Demo</DemoLink>
+          <DemoLink className={`hidden ${item} md:inline`}>Demo</DemoLink>
           <Link href={about.href} className={`hidden ${item} lg:inline`}>
             About
           </Link>
-          <a href={site.repository} className={`hidden ${item} sm:inline`}>
+          <a href={site.repository} className={`hidden ${item} md:inline`}>
             GitHub
           </a>
           <DocsSearch />
           <ThemeToggle />
           <Link
-            href={quickstartHref()}
+            href={startHref}
             className="hidden rounded-[var(--radius-control)] bg-accent px-3 py-1.5 text-micro font-medium text-accent-contrast transition-colors hover:bg-accent-hover lg:inline-block"
           >
             Get started
           </Link>
+
+          <MobileMenu>
+            <ul className="mobile-menu-list">
+              <li>
+                <Link className="mobile-menu-link" href="/">
+                  Product
+                </Link>
+              </li>
+              <li>
+                <Link className="mobile-menu-link" href={audienceIndexHref}>
+                  Who it&rsquo;s for
+                </Link>
+                <ul className="mobile-menu-sublist">
+                  {audiences.map((audience) => (
+                    <li key={audience.slug}>
+                      <Link className="mobile-menu-link" href={audienceHref(audience.slug)}>
+                        {audience.name}
+                      </Link>
+                    </li>
+                  ))}
+                </ul>
+              </li>
+              <li>
+                <Link className="mobile-menu-link" href="/docs">
+                  Docs
+                </Link>
+              </li>
+              <li>
+                <DemoLink className="mobile-menu-link">Demo</DemoLink>
+              </li>
+              <li>
+                <Link className="mobile-menu-link" href={about.href}>
+                  About
+                </Link>
+              </li>
+              <li>
+                <a className="mobile-menu-link" href={site.repository}>
+                  GitHub
+                </a>
+              </li>
+            </ul>
+            <Link className="btn btn-primary mt-4 w-full" href={startHref}>
+              Get started
+              <span aria-hidden className="btn-arrow">
+                →
+              </span>
+            </Link>
+          </MobileMenu>
         </nav>
       </div>
     </header>
diff --git a/apps/web/src/styles/globals.css b/apps/web/src/styles/globals.css
index 920c4539..35fdcfc5 100644
--- a/apps/web/src/styles/globals.css
+++ b/apps/web/src/styles/globals.css
@@ -930,6 +930,106 @@ body {
   font-size: 0.72rem;
 }
 
+.mobile-menu-button {
+  display: grid;
+  place-items: center;
+  width: 2.25rem;
+  height: 2.25rem;
+  border: 1px solid var(--border);
+  border-radius: var(--radius-control);
+  background: var(--raised);
+  color: var(--fg);
+  cursor: pointer;
+  list-style: none;
+  transition:
+    border-color 0.15s ease,
+    background-color 0.15s ease;
+}
+
+.mobile-menu-button::-webkit-details-marker {
+  display: none;
+}
+
+.mobile-menu-button:hover {
+  border-color: var(--border-strong);
+  background: var(--surface);
+}
+
+.mobile-menu-bars {
+  display: grid;
+  gap: 0.28rem;
+  width: 1rem;
+}
+
+.mobile-menu-bars > span {
+  display: block;
+  height: 1.5px;
+  border-radius: 999px;
+  background: currentColor;
+  transition:
+    transform 0.15s ease,
+    opacity 0.15s ease;
+}
+
+.mobile-menu[open] .mobile-menu-bars > span:nth-child(1) {
+  transform: translateY(0.37rem) rotate(45deg);
+}
+
+.mobile-menu[open] .mobile-menu-bars > span:nth-child(2) {
+  opacity: 0;
+}
+
+.mobile-menu[open] .mobile-menu-bars > span:nth-child(3) {
+  transform: translateY(-0.37rem) rotate(-45deg);
+}
+
+.mobile-menu-panel {
+  position: absolute;
+  inset: 100% 0 auto;
+  max-height: calc(100dvh - 4rem);
+  overflow-y: auto;
+  padding: 0.75rem 1.25rem 1.25rem;
+  border-bottom: 1px solid var(--border);
+  background: var(--canvas);
+  box-shadow: var(--lift-lg);
+}
+
+.mobile-menu-list {
+  display: flex;
+  flex-direction: column;
+}
+
+.mobile-menu-list > li + li {
+  border-top: 1px solid var(--border);
+}
+
+.mobile-menu-link {
+  display: block;
+  padding: 0.8rem 0;
+  font-size: var(--step-0);
+  font-weight: 500;
+  color: var(--fg);
+}
+
+.mobile-menu-sublist {
+  display: grid;
+  gap: 0;
+  margin: -0.25rem 0 0.5rem;
+  padding-left: 1rem;
+  border-left: 2px solid var(--border);
+}
+
+.mobile-menu-sublist .mobile-menu-link {
+  padding: 0.45rem 0;
+  font-size: var(--step--1);
+  font-weight: 400;
+  color: var(--fg-muted);
+}
+
+.mobile-menu-sublist .mobile-menu-link:hover {
+  color: var(--fg);
+}
+
 .kbd {
   border: 1px solid var(--border);
   border-radius: 4px;