feat(a11y): implement screen reader support and accessibility optimizations

components/Header.tsx

@@ -6,7 +6,7 @@ import { motion } from 'framer-motion';
 import { useTranslations } from 'next-intl';
 import { usePathname } from 'next/navigation';
 import { Button } from './ui';
-import { useEffect, useState } from 'react';
+import { useEffect, useState, useRef } from 'react';
 import { cn } from './ui';
 import { useAnalytics } from './analytics/useAnalytics';
 import { AnalyticsEvents } from './analytics/analytics-events';
@@ -17,6 +17,8 @@ export default function Header() {
   const { trackEvent } = useAnalytics();
   const [isScrolled, setIsScrolled] = useState(false);
   const [isMobileMenuOpen, setIsMobileMenuOpen] = useState(false);
+  const mobileMenuRef = useRef<HTMLDivElement>(null);
+  const closeButtonRef = useRef<HTMLButtonElement>(null);
 
   // Extract locale from pathname
   const currentLocale = pathname.split('/')[1] || 'en';
@@ -34,9 +36,52 @@ export default function Header() {
   }, []);
 
   // Prevent scroll when mobile menu is open
+  // Prevent scroll when mobile menu is open and handle focus trap
   useEffect(() => {
     if (isMobileMenuOpen) {
       document.body.style.overflow = 'hidden';
+      // Focus trap logic
+      const focusableElements = mobileMenuRef.current?.querySelectorAll(
+        'button, [href], input, select, textarea, [tabindex]:not([tabindex="-1"])',
+      );
+
+      if (focusableElements && focusableElements.length > 0) {
+        const firstElement = focusableElements[0] as HTMLElement;
+        const lastElement = focusableElements[focusableElements.length - 1] as HTMLElement;
+
+        const handleTabKey = (e: KeyboardEvent) => {
+          if (e.key === 'Tab') {
+            if (e.shiftKey) {
+              if (document.activeElement === firstElement) {
+                e.preventDefault();
+                lastElement.focus();
+              }
+            } else {
+              if (document.activeElement === lastElement) {
+                e.preventDefault();
+                firstElement.focus();
+              }
+            }
+          }
+        };
+
+        const handleEscapeKey = (e: KeyboardEvent) => {
+          if (e.key === 'Escape') {
+            setIsMobileMenuOpen(false);
+          }
+        };
+
+        document.addEventListener('keydown', handleTabKey);
+        document.addEventListener('keydown', handleEscapeKey);
+
+        // Focus the first element when menu opens
+        setTimeout(() => firstElement.focus(), 100);
+
+        return () => {
+          document.removeEventListener('keydown', handleTabKey);
+          document.removeEventListener('keydown', handleEscapeKey);
+        };
+      }
     } else {
       document.body.style.overflow = 'unset';
     }
@@ -227,6 +272,8 @@ export default function Header() {
                 textColorClass,
               )}
               aria-label={t('toggleMenu')}
+              aria-expanded={isMobileMenuOpen}
+              aria-controls="mobile-menu"
               initial={{ scale: 0.8, opacity: 0, rotate: -180 }}
               animate={{ scale: 1, opacity: 1, rotate: 0 }}
               transition={{
@@ -288,6 +335,11 @@ export default function Header() {
               ? 'opacity-100 translate-y-0'
               : 'opacity-0 -translate-y-full pointer-events-none',
           )}
+          id="mobile-menu"
+          role="dialog"
+          aria-modal="true"
+          aria-label={t('menu')}
+          ref={mobileMenuRef}
         >
           <motion.div
             className="flex-grow flex flex-col justify-center items-center p-8 space-y-8"