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

components/Lightbox.tsx

@@ -1,6 +1,6 @@
 'use client';
 
-import React, { useEffect, useState, useCallback } from 'react';
+import React, { useEffect, useState, useCallback, useRef } from 'react';
 import Image from 'next/image';
 import { createPortal } from 'react-dom';
 import { motion, AnimatePresence } from 'framer-motion';
@@ -19,6 +19,8 @@ export default function Lightbox({ isOpen, images, initialIndex, onClose }: Ligh
   const pathname = usePathname();
   const [currentIndex, setCurrentIndex] = useState(initialIndex);
   const [mounted, setMounted] = useState(false);
+  const closeButtonRef = useRef<HTMLButtonElement>(null);
+  const previousFocusRef = useRef<HTMLElement | null>(null);
 
   useEffect(() => {
     setMounted(true); // eslint-disable-line react-hooks/set-state-in-effect
@@ -76,12 +78,50 @@ export default function Lightbox({ isOpen, images, initialIndex, onClose }: Ligh
   }, [isOpen, currentIndex, updateUrl]);
 
   useEffect(() => {
-    if (!isOpen) return;
+    if (!isOpen) {
+      if (previousFocusRef.current) {
+        previousFocusRef.current.focus();
+      }
+      return;
+    }
+
+    // Capture previous focus
+    previousFocusRef.current = document.activeElement as HTMLElement;
+
+    // Focus close button on open
+    setTimeout(() => closeButtonRef.current?.focus(), 100);
 
     const handleKeyDown = (e: KeyboardEvent) => {
       if (e.key === 'Escape') handleClose();
       if (e.key === 'ArrowLeft') prevImage();
       if (e.key === 'ArrowRight') nextImage();
+
+      // Focus Trap
+      if (e.key === 'Tab') {
+        const focusableElements = document.querySelectorAll(
+          'button, [href], input, select, textarea, [tabindex]:not([tabindex="-1"])',
+        );
+        const modalElements = Array.from(focusableElements).filter((el) =>
+          document.querySelector('[role="dialog"]')?.contains(el),
+        );
+
+        if (modalElements.length === 0) return;
+
+        const firstElement = modalElements[0] as HTMLElement;
+        const lastElement = modalElements[modalElements.length - 1] as HTMLElement;
+
+        if (e.shiftKey) {
+          if (document.activeElement === firstElement) {
+            lastElement.focus();
+            e.preventDefault();
+          }
+        } else {
+          if (document.activeElement === lastElement) {
+            firstElement.focus();
+            e.preventDefault();
+          }
+        }
+      }
     };
 
     // Lock scroll
@@ -101,7 +141,11 @@ export default function Lightbox({ isOpen, images, initialIndex, onClose }: Ligh
   return createPortal(
     <AnimatePresence>
       {isOpen && (
-        <div className="fixed inset-0 z-[99999] flex items-center justify-center">
+        <div
+          className="fixed inset-0 z-[99999] flex items-center justify-center"
+          role="dialog"
+          aria-modal="true"
+        >
           <motion.div
             initial={{ opacity: 0 }}
             animate={{ opacity: 1 }}
@@ -116,6 +160,7 @@ export default function Lightbox({ isOpen, images, initialIndex, onClose }: Ligh
             animate={{ opacity: 1, scale: 1 }}
             exit={{ opacity: 0, scale: 0.5 }}
             transition={{ delay: 0.1, duration: 0.4 }}
+            ref={closeButtonRef}
             onClick={handleClose}
             className="absolute top-6 right-6 text-white/60 hover:text-white transition-all duration-500 z-[10000] rounded-full w-14 h-14 flex items-center justify-center hover:bg-white/5 group border border-white/10"
             aria-label="Close lightbox"