diff --git a/apps/app/eslint.config.js b/apps/app/eslint.config.js
index 758dc53..03d6c30 100644
--- a/apps/app/eslint.config.js
+++ b/apps/app/eslint.config.js
@@ -5,7 +5,7 @@ import reactHooks from 'eslint-plugin-react-hooks';
 import tseslint from 'typescript-eslint';
 
 export default tseslint.config(
-  {ignores: ['dist']},
+  {ignores: ['dist', 'public']},
   js.configs.recommended,
   ...tseslint.configs.recommended,
   jsxA11y.flatConfigs.recommended,
diff --git a/apps/app/index.html b/apps/app/index.html
index fdc3238..70103b9 100644
--- a/apps/app/index.html
+++ b/apps/app/index.html
@@ -9,6 +9,7 @@
     <meta name="description" content="Sign in to kwatch and manage your Pro licenses." />
     <link rel="icon" href="/favicon.svg" type="image/svg+xml" />
     <title>kwatch</title>
+    <script src="/theme-init.js"></script>
   </head>
   <body>
     <div id="root"></div>
diff --git a/apps/app/public/theme-init.js b/apps/app/public/theme-init.js
new file mode 100644
index 0000000..4e5b504
--- /dev/null
+++ b/apps/app/public/theme-init.js
@@ -0,0 +1,5 @@
+// Sets data-theme before first paint so a saved choice never flashes.
+try {
+  var t = localStorage.getItem('kwatch-theme');
+  if (t === 'light' || t === 'dark') document.documentElement.setAttribute('data-theme', t);
+} catch (e) {}
diff --git a/apps/app/src/components.tsx b/apps/app/src/components.tsx
index d25ab17..5564f9f 100644
--- a/apps/app/src/components.tsx
+++ b/apps/app/src/components.tsx
@@ -3,8 +3,10 @@ import type {ReactNode, RefObject} from 'react';
 import {NavLink, Outlet, useNavigate} from 'react-router-dom';
 import {logout, logoutAll} from './api';
 import type {ApiError} from './api';
-import {DOCS_URL, SITE_URL} from './config';
+import {BLOG_URL, DOCS_URL, GITHUB_URL, SITE_URL} from './config';
 import {useSession} from './session';
+import {useTheme} from './theme';
+import type {Theme} from './theme';
 
 export function Mark({size = 34}: {size?: number}) {
   return (
@@ -23,12 +25,116 @@ export function usePageTitle(title: string) {
   }, [title]);
 }
 
+const THEME_LABEL: Record<Theme, string> = {system: 'System', light: 'Light', dark: 'Dark'};
+
+function ThemeIcon({theme}: {theme: Theme}) {
+  const common = {
+    width: 20,
+    height: 20,
+    viewBox: '0 0 24 24',
+    fill: 'none',
+    stroke: 'currentColor',
+    strokeWidth: 2,
+    strokeLinecap: 'round' as const,
+    strokeLinejoin: 'round' as const,
+    'aria-hidden': true,
+  };
+  if (theme === 'light') {
+    return (
+      <svg {...common}>
+        <circle cx="12" cy="12" r="4" />
+        <path d="M12 2v2M12 20v2M4.9 4.9l1.4 1.4M17.7 17.7l1.4 1.4M2 12h2M20 12h2M4.9 19.1l1.4-1.4M17.7 6.3l1.4-1.4" />
+      </svg>
+    );
+  }
+  if (theme === 'dark') {
+    return (
+      <svg {...common}>
+        <path d="M21 12.8A9 9 0 1 1 11.2 3a7 7 0 0 0 9.8 9.8z" />
+      </svg>
+    );
+  }
+  return (
+    <svg {...common}>
+      <rect x="3" y="4" width="18" height="12" rx="2" />
+      <path d="M8 20h8M12 16v4" />
+    </svg>
+  );
+}
+
+export function ThemeToggle() {
+  const [theme, next] = useTheme();
+  return (
+    <button
+      type="button"
+      className="theme-toggle"
+      onClick={next}
+      aria-label={`Theme: ${THEME_LABEL[theme]}. Switch theme`}
+      title={`Theme: ${THEME_LABEL[theme]}`}
+    >
+      <ThemeIcon theme={theme} />
+    </button>
+  );
+}
+
+export function SkipLink() {
+  return (
+    <a className="skip-link" href="#main">
+      Skip to content
+    </a>
+  );
+}
+
+/** The one kwatch header: the same links on web, docs, blog and app. */
+export function SiteHeader({signedIn = false}: {signedIn?: boolean}) {
+  return (
+    <header className="site-header">
+      <a className="brand" href={SITE_URL} aria-label="kwatch home">
+        <Mark size={26} />
+        <span className="wordmark">kwatch</span>
+      </a>
+      <nav className="site-nav" aria-label="Site">
+        <a href={DOCS_URL}>Docs</a>
+        <a href={BLOG_URL}>Blog</a>
+        <a href={`${SITE_URL}/pro`}>Pro</a>
+        <a href={`${SITE_URL}/support`}>Get help</a>
+        {signedIn ? (
+          <NavLink to="/account" className="nav-account">Account</NavLink>
+        ) : (
+          <NavLink to="/signin" className="nav-account">Sign in</NavLink>
+        )}
+      </nav>
+      <ThemeToggle />
+    </header>
+  );
+}
+
+export function SiteFooter() {
+  return (
+    <footer className="site-footer">
+      <span>kwatch · source available under ELv2</span>
+      <nav aria-label="Footer">
+        <a href={DOCS_URL}>Docs</a>
+        <a href={BLOG_URL}>Blog</a>
+        <a href={GITHUB_URL}>GitHub</a>
+        <a href={`${SITE_URL}/support`}>Get help</a>
+        <a href={`${SITE_URL}/privacy`}>Privacy</a>
+        <a href={`${SITE_URL}/terms`}>Terms</a>
+      </nav>
+    </footer>
+  );
+}
+
 /** Centered card used by the sign-in screens and the 404. */
 export function Card({children}: {children: ReactNode}) {
   return (
-    <main className="center">
-      <div className="card">{children}</div>
-    </main>
+    <>
+      <SkipLink />
+      <SiteHeader />
+      <main id="main" className="center">
+        <div className="card">{children}</div>
+      </main>
+    </>
   );
 }
 
@@ -57,36 +163,30 @@ export function Shell() {
   }
 
   return (
-    <div className="shell">
-      <nav className="side" aria-label="App">
-        <span className="brand">
-          <Mark size={26} />
-          <span className="wordmark">kwatch</span>
-        </span>
-        <NavLink to="/licenses">Licenses</NavLink>
-        <NavLink to="/help">Get help</NavLink>
-        <NavLink to="/account">Account</NavLink>
-        <a className="muted-link" href={DOCS_URL}>
-          Docs ↗
-        </a>
-        <a className="muted-link" href={SITE_URL}>
-          kwatch.dev ↗
-        </a>
-        <span className="who">
-          {data.account.email} ·{' '}
-          <button type="button" className="link" onClick={() => signOut()}>
-            Sign out
-          </button>
-          {signOutError && <span className="alert" role="alert">{signOutError}</span>}
-        </span>
-      </nav>
-      <div className="main">
-        <main className="content">
-          <Outlet />
-        </main>
-        <footer className="site-footer">kwatch · source available under ELv2</footer>
+    <>
+      <SkipLink />
+      <SiteHeader signedIn />
+      <div className="shell">
+        <nav className="side" aria-label="App">
+          <NavLink to="/licenses">Licenses</NavLink>
+          <NavLink to="/help">Get help</NavLink>
+          <NavLink to="/account">Account</NavLink>
+          <span className="who">
+            {data.account.email} ·{' '}
+            <button type="button" className="link" onClick={() => signOut()}>
+              Sign out
+            </button>
+            {signOutError && <span className="alert" role="alert">{signOutError}</span>}
+          </span>
+        </nav>
+        <div className="main">
+          <main id="main" className="content" tabIndex={-1}>
+            <Outlet />
+          </main>
+          <SiteFooter />
+        </div>
       </div>
-    </div>
+    </>
   );
 }
 
diff --git a/apps/app/src/config.ts b/apps/app/src/config.ts
index b8417d9..84f7be7 100644
--- a/apps/app/src/config.ts
+++ b/apps/app/src/config.ts
@@ -7,6 +7,8 @@ export const TURNSTILE_SITEKEY: string = env.VITE_TURNSTILE_SITEKEY ?? '0x4AAAAA
 
 export const SITE_URL = 'https://kwatch.dev';
 export const DOCS_URL = 'https://docs.kwatch.dev';
+export const BLOG_URL = 'https://blog.kwatch.dev';
+export const GITHUB_URL = 'https://github.com/abahmed/kwatch';
 export const CONTACT_URL = 'mailto:hello@kwatch.dev';
 export const SUPPORT_EMAIL = 'support@kwatch.dev';
 export const SUPPORT_MAILTO = `mailto:${SUPPORT_EMAIL}`;
diff --git a/apps/app/src/pages/Licenses.tsx b/apps/app/src/pages/Licenses.tsx
index 992ef1c..cc68491 100644
--- a/apps/app/src/pages/Licenses.tsx
+++ b/apps/app/src/pages/Licenses.tsx
@@ -354,7 +354,7 @@ export default function Licenses() {
   }
 
   const button = (
-    <button type="button" className="btn btn-signal" disabled={busy} onClick={getFree}>
+    <button type="button" className="btn btn-primary" disabled={busy} onClick={getFree}>
       {busy ? 'Getting your license…' : 'Get a free Pro license'}
     </button>
   );
diff --git a/apps/app/src/styles.css b/apps/app/src/styles.css
index c487806..3c5c055 100644
--- a/apps/app/src/styles.css
+++ b/apps/app/src/styles.css
@@ -28,25 +28,49 @@ code, .mono { font-family: var(--font-mono); }
 /* Controls */
 button { font: inherit; cursor: pointer; }
 button:disabled { cursor: not-allowed; }
-.btn:disabled { background: var(--surface); color: var(--text-muted); border-color: var(--line); }
-:focus-visible { outline: var(--focus-width) solid var(--text); outline-offset: var(--focus-offset); }
-.btn {
+:focus-visible { outline: var(--focus-width) solid var(--text); outline-offset: var(--focus-offset); border-radius: 4px; }
+/*
+  One button spec (rows 3, 21, 25): pill, 44px, 1.5px border, 11px 22px.
+  Line = --text label on --control-border; solid = --text fill with the opposite token
+  (--bg) as label. Every state sets color explicitly so link defaults cannot win.
+*/
+.btn, .btn-action {
   background: transparent; color: var(--text);
   border: var(--btn-border) solid var(--control-border); border-radius: var(--radius-pill);
-  min-height: var(--btn-height); padding: 0 18px; font-weight: 600; font-size: 15px;
+  min-height: var(--btn-height); padding: 11px 22px; font-weight: 600; font-size: 15px; line-height: 1.2;
   display: inline-flex; align-items: center; justify-content: center; text-decoration: none;
 }
-.btn-sm { min-height: var(--hit); padding: 0 14px; font-size: 14px; font-weight: 500; }
-.btn-primary { background: var(--text); color: var(--bg); border-color: var(--text); }
-.btn-signal { background: var(--signal); color: var(--on-signal); border-color: var(--signal); font-weight: 600; }
-.btn-danger { color: var(--failing); border-color: var(--failing); }
+.btn:visited, .btn-action:visited { color: var(--text); }
+.btn:hover:not(:disabled), .btn:focus-visible, .btn-action:hover:not(:disabled), .btn-action:focus-visible {
+  background: var(--text); color: var(--bg); border-color: var(--text);
+}
+.btn:active:not(:disabled), .btn-action:active:not(:disabled) { background: var(--text); color: var(--bg); border-color: var(--text); }
+.btn-sm { padding: 11px 18px; font-size: 14px; font-weight: 500; }
+.btn-primary, .btn-primary:visited, .btn-action.is-primary, .btn-action.is-primary:visited {
+  background: var(--text); color: var(--bg); border-color: var(--text);
+}
+.btn-primary:hover:not(:disabled), .btn-primary:focus-visible, .btn-primary:active:not(:disabled),
+.btn-action.is-primary:hover:not(:disabled), .btn-action.is-primary:focus-visible, .btn-action.is-primary:active:not(:disabled) {
+  background: var(--primary-hover); color: var(--bg); border-color: var(--primary-hover);
+}
+.btn-danger, .btn-danger:visited { color: var(--failing); border-color: var(--failing); }
+.btn-danger:hover:not(:disabled), .btn-danger:focus-visible, .btn-danger:active:not(:disabled) {
+  background: var(--failing); color: var(--bg); border-color: var(--failing);
+}
+.btn:disabled, .btn-action:disabled, .btn-primary:disabled, .btn-action.is-primary:disabled, .btn-danger:disabled {
+  background: var(--surface); color: var(--text-muted); border-color: var(--line); cursor: not-allowed;
+}
 .btn-block { width: 100%; margin-top: 14px; padding: 13px; }
+/* Signal areas: labels, borders and icons use --on-signal, never --text (row 22). */
+.on-signal { background: var(--signal); color: var(--on-signal); }
+.on-signal a, .on-signal .btn-line, .on-signal svg { color: var(--on-signal); border-color: var(--on-signal); }
+.on-signal .btn-solid { background: var(--ink); color: var(--ink-text); border-color: var(--ink); }
 .link { background: none; border: 0; padding: 0; color: var(--text); text-decoration: underline; }
 label { display: block; margin-top: 22px; font-size: 14px; font-weight: 600; }
 input {
   display: block; width: 100%; margin-top: 6px; padding: 12px 14px;
   background: var(--bg); color: var(--text);
-  border: 1.5px solid var(--text); border-radius: var(--radius-input); font: inherit;
+  border: 1.5px solid var(--control-border); border-radius: var(--radius-input); font: inherit;
 }
 .check { margin-top: 12px; min-height: 65px; display: flex; align-items: center; }
 
@@ -65,7 +89,7 @@ input {
 .limit a, .notice-warn a { color: var(--text); }
 
 /* Centered screens */
-.center { min-height: 100vh; display: grid; place-items: center; padding: 24px 16px; }
+.center { min-height: calc(100vh - 69px); display: grid; place-items: center; padding: 24px 16px; }
 .card { width: 100%; max-width: 440px; border: 1px solid var(--line); border-radius: var(--radius-card); padding: 36px; }
 .card h1 { margin-top: 12px; }
 .card .mark + h1 { margin-top: 18px; }
@@ -76,8 +100,40 @@ input {
 .back a { color: var(--text-muted); }
 form .muted.small { margin-top: 14px; font-size: 13px; }
 
+/* Skip link and shared header */
+.skip-link {
+  position: absolute; top: -100px; left: 12px; z-index: 20;
+  background: var(--text); color: var(--bg); padding: 11px 22px; border-radius: var(--radius-pill);
+  font-weight: 600; text-decoration: none;
+}
+.skip-link:focus, .skip-link:focus-visible { top: 12px; color: var(--bg); }
+.site-header {
+  display: flex; align-items: center; gap: var(--space-3) var(--space-5);
+  padding: var(--space-3) var(--space-6); border-bottom: 1px solid var(--line);
+}
+.site-header .brand { margin: 0; text-decoration: none; min-height: var(--hit); }
+.site-nav { display: flex; align-items: center; flex-wrap: wrap; gap: 0 var(--space-2); margin-left: auto; font-size: 15px; }
+.site-nav a {
+  display: inline-flex; align-items: center; min-height: var(--hit); padding: 0 var(--space-3);
+  color: var(--text); text-decoration: none;
+}
+.site-nav a:hover { text-decoration: underline; text-underline-offset: 3px; }
+.site-nav a[aria-current="page"] { text-decoration: underline; text-underline-offset: 3px; }
+.site-nav .nav-account { font-weight: 700; }
+.theme-toggle {
+  display: inline-flex; align-items: center; justify-content: center; width: var(--hit); height: var(--hit); padding: 0;
+  background: transparent; color: var(--text); border: var(--btn-border) solid var(--control-border); border-radius: var(--radius-pill);
+}
+.theme-toggle:hover { background: var(--text); color: var(--bg); border-color: var(--text); }
+@media (max-width: 700px) {
+  .site-header { flex-wrap: wrap; padding: var(--space-3) var(--space-4); }
+  .site-header .theme-toggle { margin-left: auto; }
+  .site-nav { order: 3; flex-basis: 100%; margin-left: calc(-1 * var(--space-2)); gap: 0; }
+  .site-nav a { padding: 0 var(--space-2); }
+}
+
 /* Shell */
-.shell { display: grid; grid-template-columns: 220px 1fr; min-height: 100vh; }
+.shell { display: grid; grid-template-columns: 220px 1fr; min-height: calc(100vh - 69px); }
 .side {
   border-right: 1px solid var(--line); padding: 26px 22px;
   display: flex; flex-direction: column; gap: 12px; font-size: 15px;
@@ -90,7 +146,13 @@ form .muted.small { margin-top: 14px; font-size: 13px; }
 .who .link { color: var(--text-muted); }
 .main { display: flex; flex-direction: column; min-width: 0; }
 .content { padding: var(--space-6) var(--space-6); max-width: var(--max-app); width: 100%; flex: 1; }
-.site-footer { padding: var(--space-4) var(--space-6); max-width: var(--max-app); width: 100%; font-size: 14px; color: var(--text-muted); }
+.site-footer {
+  padding: var(--space-4) var(--space-6); max-width: var(--max-app); width: 100%; font-size: 14px; color: var(--text-soft);
+  display: flex; flex-wrap: wrap; gap: var(--space-2) var(--space-5); align-items: center;
+}
+.site-footer nav { display: flex; flex-wrap: wrap; gap: 0 var(--space-4); }
+.site-footer a { color: var(--text-soft); display: inline-flex; align-items: center; min-height: var(--hit); text-underline-offset: 3px; }
+.site-footer a:hover { color: var(--text); }
 .page-head { display: flex; flex-wrap: wrap; justify-content: space-between; align-items: baseline; gap: 12px; }
 .page-head h1 { font-size: 34px; }
 
@@ -129,21 +191,14 @@ form .muted.small { margin-top: 14px; font-size: 13px; }
 .license-footer { display: flex; flex-wrap: wrap; gap: 8px 16px; padding: 16px 22px; border-top: 1px solid var(--line); }
 .license-group { display: flex; flex-wrap: wrap; gap: 8px; }
 .license-group-manage { margin-inline-start: auto; }
-.btn-action {
-  min-height: var(--btn-height); padding: 0 18px; font-size: 15px; font-weight: 500;
-  border: var(--btn-border) solid var(--control-border); border-radius: var(--radius-pill);
-  background: transparent; color: var(--text);
-}
+.btn-action { font-weight: 500; }
 .btn-action.is-toggle { min-width: 112px; }
-.btn-action:hover:not(:disabled) { background: var(--surface); border-color: var(--text); }
-.btn-action:active:not(:disabled) { background: var(--line); }
-.btn-action.is-primary { background: var(--text); color: var(--bg); border-color: var(--text); font-weight: 600; min-width: 112px; }
-.btn-action.is-primary:hover:not(:disabled) { background: var(--primary-hover); border-color: var(--primary-hover); }
-.btn-action.is-primary:active:not(:disabled) { background: var(--primary-hover); transform: translateY(1px); }
-.btn-action:disabled, .btn-action.is-primary:disabled { background: var(--surface); color: var(--text-muted); border-color: var(--line); cursor: not-allowed; }
-.btn-quiet { border-color: transparent; color: var(--text-muted); padding: 0 12px; }
-.btn-quiet:hover:not(:disabled) { background: transparent; border-color: transparent; color: var(--text); text-decoration: underline; }
-.btn-quiet:active:not(:disabled) { background: transparent; color: var(--text); }
+.btn-action.is-primary { font-weight: 600; min-width: 112px; }
+.btn-quiet, .btn-quiet:visited { border-color: transparent; background: transparent; color: var(--text-soft); padding: 11px 12px; }
+.btn-quiet:hover:not(:disabled), .btn-quiet:focus-visible, .btn-quiet:active:not(:disabled) {
+  background: transparent; border-color: transparent; color: var(--text); text-decoration: underline;
+}
+.btn-quiet:disabled { background: transparent; border-color: transparent; }
 @media (prefers-reduced-motion: no-preference) {
   .btn-action { transition: background-color 120ms, border-color 120ms; }
 }
@@ -254,7 +309,6 @@ form .muted.small { margin-top: 14px; font-size: 13px; }
 @media (prefers-reduced-motion: reduce) { .spinner { animation-duration: 2s; } }
 .icon-btn { display: inline-flex; align-items: center; justify-content: center; width: 36px; height: 36px; padding: 0; background: none; border: 0; border-radius: var(--radius-pill); color: var(--text-muted); cursor: pointer; transition: background var(--motion-fast), color var(--motion-fast); }
 .icon-btn:hover:not(:disabled) { color: var(--text); background: color-mix(in srgb, var(--text) 8%, transparent); }
-.icon-btn:focus-visible { outline: 2px solid var(--text); outline-offset: 2px; }
 .icon-btn:disabled { color: var(--text-muted); cursor: default; }
 .key-row { display: flex; align-items: center; gap: var(--space-1); min-width: 0; }
 .key-row .key { margin: 0; overflow-x: auto; }
diff --git a/apps/app/src/theme.ts b/apps/app/src/theme.ts
new file mode 100644
index 0000000..42f67b0
--- /dev/null
+++ b/apps/app/src/theme.ts
@@ -0,0 +1,38 @@
+import {useCallback, useState} from 'react';
+
+export type Theme = 'system' | 'light' | 'dark';
+const KEY = 'kwatch-theme';
+
+export function readTheme(): Theme {
+  try {
+    const t = localStorage.getItem(KEY);
+    if (t === 'light' || t === 'dark') return t;
+  } catch {
+    /* storage blocked: stay on System */
+  }
+  return 'system';
+}
+
+export function applyTheme(theme: Theme) {
+  const root = document.documentElement;
+  if (theme === 'system') root.removeAttribute('data-theme');
+  else root.setAttribute('data-theme', theme);
+  try {
+    if (theme === 'system') localStorage.removeItem(KEY);
+    else localStorage.setItem(KEY, theme);
+  } catch {
+    /* storage blocked: the choice lasts for this page only */
+  }
+}
+
+const ORDER: Theme[] = ['system', 'light', 'dark'];
+
+export function useTheme(): [Theme, () => void] {
+  const [theme, setTheme] = useState<Theme>(readTheme);
+  const next = useCallback(() => {
+    const n = ORDER[(ORDER.indexOf(theme) + 1) % ORDER.length];
+    applyTheme(n);
+    setTheme(n);
+  }, [theme]);
+  return [theme, next];
+}