diff --git a/web/src/components/layout/AppShell.tsx b/web/src/components/layout/AppShell.tsx
index 88442b2..4fe42f1 100644
--- a/web/src/components/layout/AppShell.tsx
+++ b/web/src/components/layout/AppShell.tsx
@@ -1,10 +1,14 @@
-import { Link, Outlet, useNavigate } from '@tanstack/react-router'
+import { useState } from 'react'
+import { Link, Outlet, useMatchRoute, useNavigate } from '@tanstack/react-router'
 import { Toaster } from '@/components/ui/toast'
 import { useLogout, useMe } from '@/lib/auth'
 
-const navLinks = [
-  { to: '/gardens', label: 'Gardens' },
-  { to: '/plants', label: 'Plants' },
+// Top-level sections. `icon` is only used by the mobile bottom bar; the desktop
+// top bar shows labels alone. Settings is filtered to admins at render.
+const sections = [
+  { to: '/gardens', label: 'Gardens', icon: '🏡', adminOnly: false },
+  { to: '/plants', label: 'Plants', icon: '🌿', adminOnly: false },
+  { to: '/settings', label: 'Settings', icon: '⚙️', adminOnly: true },
 ] as const
 
 // TanStack Router concatenates the base className with activeProps/inactiveProps,
@@ -14,73 +18,56 @@ const navLinkBase = 'rounded-md px-3 py-1.5 text-sm font-medium transition-color
 const navLinkActive = 'bg-border/60 text-fg'
 const navLinkInactive = 'text-muted hover:bg-border/60 hover:text-fg'
 
-/** Top-level chrome: a sticky nav bar plus the routed page in an <Outlet>. */
+/**
+ * Top-level chrome. Mobile-first: a slim top bar (brand + account) with the
+ * section nav moved to a thumb-reachable bottom tab bar; the desktop breakpoint
+ * (`md:`) restores the inline top nav. The editor is a full-screen context, so it
+ * owns the bottom of the screen — the app bottom bar hides there (the brand link
+ * is the way back to the gardens list), leaving exactly one bottom bar per route.
+ */
 export function AppShell() {
   const me = useMe()
-  const logout = useLogout()
-  const navigate = useNavigate()
   const user = me.data
+  const matchRoute = useMatchRoute()
 
-  async function onLogout() {
-    try {
-      await logout.mutateAsync()
-      await navigate({ to: '/login' })
-    } catch {
-      // The logout request failed, so the session is still valid server-side:
-      // leave the user where they are (the button re-enables for a retry) rather
-      // than pretending they're signed out. logout.isError drives the title below.
-    }
-  }
+  // The garden editor route ('/gardens/$gardenId') runs full-screen. Fuzzy:false
+  // so the '/gardens' list itself still shows the bottom bar.
+  const inEditor = !!matchRoute({ to: '/gardens/$gardenId', fuzzy: false })
+  const showBottomNav = !!user && !inEditor
+
+  const visibleSections = sections.filter((s) => !s.adminOnly || user?.isAdmin)
 
   return (
     <div className="flex min-h-full flex-col">
-      <header className="sticky top-0 z-10 border-b border-border bg-surface/90 backdrop-blur">
+      <header className="sticky top-0 z-20 border-b border-border bg-surface/90 backdrop-blur">
         <nav className="mx-auto flex max-w-5xl items-center gap-4 px-4 py-3">
           <Link to="/gardens" className="text-lg font-semibold text-accent-strong">
             🌱 pansy
           </Link>
 
-          <div className="flex flex-1 items-center gap-1">
+          {/* Desktop inline section links. Hidden on mobile, where the bottom bar
+              carries them. */}
+          <div className="hidden flex-1 items-center gap-1 md:flex">
             {user &&
-              navLinks.map((l) => (
+              visibleSections.map((s) => (
                 <Link
-                  key={l.to}
-                  to={l.to}
+                  key={s.to}
+                  to={s.to}
                   className={navLinkBase}
                   activeProps={{ className: navLinkActive }}
                   inactiveProps={{ className: navLinkInactive }}
                 >
-                  {l.label}
+                  {s.label}
                 </Link>
               ))}
-            {/* Settings is admin-only, matching the server's requireAdmin gate.
-                A non-admin who typed /settings still gets a 403 from the API — the
-                hidden link is convenience, not the security boundary. */}
-            {user?.isAdmin && (
-              <Link
-                to="/settings"
-                className={navLinkBase}
-                activeProps={{ className: navLinkActive }}
-                inactiveProps={{ className: navLinkInactive }}
-              >
-                Settings
-              </Link>
-            )}
           </div>
 
+          {/* Spacer so account/sign-out sits right on mobile (the desktop links
+              own flex-1 above). */}
+          <div className="flex-1 md:hidden" />
+
           {user ? (
-            <div className="flex items-center gap-2">
-              <span className="hidden text-sm text-muted sm:inline">{user.displayName}</span>
-              <button
-                type="button"
-                onClick={onLogout}
-                disabled={logout.isPending}
-                title={logout.isError ? 'Sign out failed — try again' : undefined}
-                className="rounded-md px-3 py-1.5 text-sm font-medium text-muted transition-colors hover:text-fg disabled:opacity-60"
-              >
-                {logout.isPending ? 'Signing out…' : logout.isError ? 'Retry sign out' : 'Sign out'}
-              </button>
-            </div>
+            <AccountMenu displayName={user.displayName} />
           ) : (
             <Link
               to="/login"
@@ -92,11 +79,123 @@ export function AppShell() {
         </nav>
       </header>
 
-      <main className="mx-auto w-full max-w-5xl flex-1 px-4 py-6">
+      {/* Bottom bar clearance on mobile so content isn't hidden behind it. */}
+      <main
+        className={`mx-auto w-full max-w-5xl flex-1 px-4 py-6 ${
+          showBottomNav ? 'pb-[calc(4.5rem+env(safe-area-inset-bottom))] md:pb-6' : ''
+        }`}
+      >
         <Outlet />
       </main>
 
+      {showBottomNav && <BottomNav sections={visibleSections} />}
+
       <Toaster />
     </div>
   )
 }
+
+/** Account control: a compact button that toggles a small sign-out popover. On
+ *  desktop the display name shows inline; on mobile it lives inside the popover. */
+function AccountMenu({ displayName }: { displayName: string }) {
+  const logout = useLogout()
+  const navigate = useNavigate()
+  const [open, setOpen] = useState(false)
+
+  async function onLogout() {
+    try {
+      await logout.mutateAsync()
+      await navigate({ to: '/login' })
+    } catch {
+      // The logout request failed, so the session is still valid server-side:
+      // leave the user where they are (the button re-enables for a retry) rather
+      // than pretending they're signed out. logout.isError drives the label.
+      setOpen(false)
+    }
+  }
+
+  const initial = displayName.trim().charAt(0).toUpperCase() || '·'
+
+  return (
+    <div className="relative">
+      <button
+        type="button"
+        onClick={() => setOpen((v) => !v)}
+        aria-haspopup="menu"
+        aria-expanded={open}
+        className="flex items-center gap-2 rounded-md px-2 py-1.5 text-sm text-muted transition-colors hover:text-fg"
+      >
+        <span className="hidden sm:inline">{displayName}</span>
+        <span
+          aria-hidden
+          className="flex size-8 items-center justify-center rounded-full bg-border/60 text-sm font-semibold text-fg"
+        >
+          {initial}
+        </span>
+      </button>
+
+      {open && (
+        <>
+          {/* Full-screen click-away backdrop; reliably closes on an outside tap
+              without a document listener. */}
+          <button
+            type="button"
+            aria-label="Close menu"
+            className="fixed inset-0 z-30 cursor-default"
+            onClick={() => setOpen(false)}
+          />
+          <div
+            role="menu"
+            className="absolute right-0 z-40 mt-2 w-48 rounded-lg border border-border bg-surface p-1 shadow-lg"
+          >
+            <p className="truncate px-3 py-2 text-xs text-muted">
+              Signed in as <span className="text-fg">{displayName}</span>
+            </p>
+            <button
+              type="button"
+              role="menuitem"
+              onClick={onLogout}
+              disabled={logout.isPending}
+              title={logout.isError ? 'Sign out failed — try again' : undefined}
+              className="w-full rounded-md px-3 py-2 text-left text-sm font-medium text-muted transition-colors hover:bg-border/60 hover:text-fg disabled:opacity-60"
+            >
+              {logout.isPending ? 'Signing out…' : logout.isError ? 'Retry sign out' : 'Sign out'}
+            </button>
+          </div>
+        </>
+      )}
+    </div>
+  )
+}
+
+/** Mobile bottom tab bar for the top-level sections (thumb zone, safe-area aware). */
+function BottomNav({
+  sections,
+}: {
+  sections: ReadonlyArray<{ to: string; label: string; icon: string }>
+}) {
+  return (
+    <nav
+      aria-label="Sections"
+      className="fixed inset-x-0 bottom-0 z-20 border-t border-border bg-surface/95 pb-[env(safe-area-inset-bottom)] backdrop-blur md:hidden"
+    >
+      <ul className="mx-auto flex max-w-5xl items-stretch justify-around">
+        {sections.map((s) => (
+          <li key={s.to} className="flex-1">
+            <Link
+              to={s.to}
+              className="flex min-h-[3.25rem] flex-col items-center justify-center gap-0.5 py-1.5 text-xs font-medium text-muted transition-colors"
+              activeProps={{ className: 'text-accent-strong' }}
+              inactiveProps={{ className: 'text-muted hover:text-fg' }}
+            >
+              <span aria-hidden className="text-lg leading-none">
+                {s.icon}
+              </span>
+              {s.label}
+            </Link>
+          </li>
+        ))}
+      </ul>
+    </nav>
+  )
+}