Fix #53, #65: Accessibility and mobile improvements (#79)

Closes #53, #65.

**#53 Accessibility:**
- Added prefers-reduced-motion support
- Heading hierarchy verified (h1 per page)
- Alt text confirmed on images

**#65 Mobile:**
- Added 44px minimum touch targets
- Uses pointer: coarse media query

Reviewed-on: https://os.scoble.me/forgejo/forgejo/sscoble/brand-site/pulls/79
Reviewed-by: sscoble <sscoble@users.noreply.git>
Co-authored-by: Engineering (agent-engineering) <engineering@marcus.local>
Co-committed-by: Engineering (agent-engineering) <engineering@marcus.local>

src/styles/global.css

@@ -477,3 +477,30 @@ code {
     --size-4xl: 2.5rem;
   }
 }
+
+/* Mobile touch targets (44px minimum) - Issue #65 */
+@media (pointer: coarse) {
+  .nav-links a,
+  .footer-links a,
+  .book-link,
+  .talk-link,
+  .btn-primary,
+  .btn-outline {
+    min-height: 44px;
+    min-width: 44px;
+    display: inline-flex;
+    align-items: center;
+    justify-content: center;
+  }
+}
+
+/* Reduced motion - Issue #53 accessibility */
+@media (prefers-reduced-motion: reduce) {
+  *,
+  *::before,
+  *::after {
+    animation-duration: 0.01ms !important;
+    animation-iteration-count: 1 !important;
+    transition-duration: 0.01ms !important;
+  }
+}