diff --git a/src/App.css b/src/App.css
index b64d3ce..2653567 100644
--- a/src/App.css
+++ b/src/App.css
@@ -60,7 +60,10 @@ h1, h2, h3, h4, p {
 
 .site-shell {
   width: 100%;
-  overflow-x: hidden;
+  /* clip (not hidden) contains horizontal overflow without turning the
+     shell into a scroll container — which would force overflow-y to `auto`
+     and break the sticky nav's position. */
+  overflow-x: clip;
   min-height: 100vh;
   background:
     radial-gradient(ellipse at 50% -10%, rgba(138,180,248,0.20) 0%, transparent 52%),
diff --git a/src/App.jsx b/src/App.jsx
index 53d2c4b..22a2d48 100644
--- a/src/App.jsx
+++ b/src/App.jsx
@@ -339,7 +339,7 @@ function Waitlist() {
             <Mail size={15} className="signup-field-icon" />
             <input name="email" type="email" placeholder="you@example.com" required />
           </div>
-          <button disabled={status === 'loading'}>
+          <button disabled={status === 'loading'} aria-busy={status === 'loading'}>
             {status === 'loading' ? 'Setting up…' : 'Continue'}
             <ArrowRight size={15} />
           </button>
@@ -361,15 +361,17 @@ function Waitlist() {
 
         <p className="signup-platform">Requires iPhone · iOS 17 or later</p>
 
-        {status === 'success' && (
-          <p className="form-note">You&apos;re in. We&apos;ll email your TestFlight invite when a spot opens.</p>
-        )}
-        {status === 'error' && (
-          <p className="form-note error">
-            Something went wrong. Try{' '}
-            <a href="mailto:m.rafiq2006@icloud.com">m.rafiq2006@icloud.com</a>.
-          </p>
-        )}
+        <div className="waitlist-status" role="status" aria-live="polite">
+          {status === 'success' && (
+            <p className="form-note">You&apos;re in. We&apos;ll email your TestFlight invite when a spot opens.</p>
+          )}
+          {status === 'error' && (
+            <p className="form-note error">
+              Something went wrong. Try{' '}
+              <a href="mailto:m.rafiq2006@icloud.com">m.rafiq2006@icloud.com</a>.
+            </p>
+          )}
+        </div>
       </FadeIn>
     </section>
   );
@@ -385,6 +387,7 @@ function SiteShell() {
     <AmbientContext.Provider value={ambient.setAmbient}>
       <PhoneProvider onAmbientChange={ambient.setAmbient}>
         <main className="site-shell">
+          <a className="skip-link" href="#top">Skip to content</a>
           <AmbientBackdrop colors={ambient.colors} front={ambient.front} />
           <div className="grain" />
 
diff --git a/src/a11y-polish.css b/src/a11y-polish.css
new file mode 100644
index 0000000..3c44688
--- /dev/null
+++ b/src/a11y-polish.css
@@ -0,0 +1,105 @@
+/* =====================================================
+   LUMEN - Accessibility & interaction polish
+   Keyboard focus visibility, skip link, anchor-scroll
+   offset under the sticky nav, and reduced-motion-aware
+   smooth scrolling. Layered on top of the existing chrome
+   so the visual design is untouched for mouse users.
+   ===================================================== */
+
+:root {
+  --focus-ring: rgba(138, 180, 248, 0.95);
+}
+
+html[data-theme='light'] {
+  --focus-ring: rgba(79, 111, 208, 0.95);
+}
+
+/* ===== KEYBOARD FOCUS VISIBILITY =====
+   Only shows for keyboard/AT users (:focus-visible), so mouse
+   clicks stay ring-free. Outline follows each element's own
+   border-radius in modern browsers, so rounded controls stay round. */
+
+a:focus-visible,
+button:focus-visible,
+input:focus-visible,
+select:focus-visible,
+textarea:focus-visible,
+[tabindex]:focus-visible {
+  outline: 2px solid var(--focus-ring);
+  outline-offset: 3px;
+}
+
+/* The waitlist input clears its outline explicitly (class specificity),
+   so restore a visible focus ring for keyboard users at matching weight. */
+.waitlist-form input:focus-visible {
+  outline: 2px solid var(--focus-ring);
+  outline-offset: 2px;
+}
+
+/* ===== SKIP TO CONTENT =====
+   Off-screen until focused, then slides into the top-left so a
+   keyboard user can jump past the nav on the first Tab press. */
+
+.skip-link {
+  position: fixed;
+  top: 12px;
+  left: 12px;
+  z-index: 100;
+  padding: 10px 16px;
+  border-radius: 10px;
+  background: var(--cta-bg, #8ab4f8);
+  color: var(--cta-text, #0a0c12);
+  font-size: 13px;
+  font-weight: 600;
+  letter-spacing: 0.01em;
+  box-shadow: 0 12px 30px -12px rgba(138, 180, 248, 0.7);
+  transform: translateY(-160%);
+  transition: transform 0.18s ease;
+}
+
+.skip-link:focus {
+  transform: translateY(0);
+  outline: 2px solid var(--focus-ring);
+  outline-offset: 3px;
+}
+
+@media (prefers-reduced-motion: reduce) {
+  .skip-link {
+    transition: none;
+  }
+}
+
+/* ===== ANCHOR-SCROLL OFFSET =====
+   The nav is sticky, so bare #anchor jumps land section headings
+   underneath it. Reserve the nav's height at the top of every
+   scroll so targets settle just below it. */
+
+html {
+  scroll-padding-top: 88px;
+}
+
+@media (max-width: 600px) {
+  html {
+    scroll-padding-top: 72px;
+  }
+}
+
+/* ===== SMOOTH IN-PAGE SCROLLING ===== */
+
+@media (prefers-reduced-motion: no-preference) {
+  html {
+    scroll-behavior: smooth;
+  }
+}
+
+/* ===== BRAND-TINTED TEXT SELECTION ===== */
+
+::selection {
+  background: rgba(138, 180, 248, 0.28);
+  color: var(--text-heading, #f7f9fc);
+}
+
+html[data-theme='light'] ::selection {
+  background: rgba(79, 111, 208, 0.22);
+  color: var(--text-heading, #0f1322);
+}
diff --git a/src/main.jsx b/src/main.jsx
index 6cc76cf..a7fcada 100644
--- a/src/main.jsx
+++ b/src/main.jsx
@@ -4,6 +4,7 @@ import { createRoot } from 'react-dom/client';
 import { App } from './App.jsx';
 import './lumen-overrides.css';
 import './mobile-polish.css';
+import './a11y-polish.css';
 
 const root = document.getElementById('root');
 
diff --git a/src/mobile-polish.css b/src/mobile-polish.css
index ec1d6e7..cf3ddc6 100644
--- a/src/mobile-polish.css
+++ b/src/mobile-polish.css
@@ -255,7 +255,7 @@
 
 @media (max-width: 600px) {
   .site-shell {
-    overflow-x: hidden;
+    overflow-x: clip;
   }
 
   .nav {