Enhance accessibility and improve form semantics across multiple pages

- Added `htmlFor` attributes to labels for better accessibility in Calendar, Dashboard, GuestJoin, Login, Register, RoomDetail, and Settings pages.
- Included `aria-hidden` attributes for icons to improve screen reader experience.
- Set `autoComplete` attributes for input fields to enhance user experience during form filling.
- Implemented `role` and `aria` attributes for radio groups and buttons to improve accessibility compliance.

src/components/Modal.jsx

@@ -1,15 +1,49 @@
+import { useEffect, useId, useRef } from 'react';
 import { X } from 'lucide-react';
+import { useLanguage } from '../contexts/LanguageContext';
 
 export default function Modal({ title, children, onClose, maxWidth = 'max-w-lg' }) {
+  const { t } = useLanguage();
+  const titleId = useId();
+  const dialogRef = useRef(null);
+  const previouslyFocused = useRef(null);
+
+  useEffect(() => {
+    previouslyFocused.current = document.activeElement;
+    const handleKey = (e) => {
+      if (e.key === 'Escape') onClose?.();
+    };
+    document.addEventListener('keydown', handleKey);
+    // Focus the dialog so screen readers announce it and keyboard focus lands inside
+    dialogRef.current?.focus();
+    return () => {
+      document.removeEventListener('keydown', handleKey);
+      previouslyFocused.current?.focus?.();
+    };
+  }, [onClose]);
+
   return (
     <div className="fixed inset-0 z-50 flex items-center justify-center p-4">
-      <div className="fixed inset-0 bg-black/60 backdrop-blur-xs" onClick={onClose} />
-      <div className={`relative bg-th-card rounded-2xl border border-th-border shadow-2xl w-full ${maxWidth}`}>
+      <div
+        className="fixed inset-0 bg-black/60 backdrop-blur-xs"
+        onClick={onClose}
+        aria-hidden="true"
+      />
+      <div
+        ref={dialogRef}
+        role="dialog"
+        aria-modal="true"
+        aria-labelledby={titleId}
+        tabIndex={-1}
+        className={`relative bg-th-card rounded-2xl border border-th-border shadow-2xl w-full ${maxWidth} focus:outline-hidden`}
+      >
         {/* Header */}
         <div className="flex items-center justify-between px-6 py-4 border-b border-th-border rounded-t-2xl">
-          <h2 className="text-lg font-semibold text-th-text">{title}</h2>
+          <h2 id={titleId} className="text-lg font-semibold text-th-text">{title}</h2>
           <button
+            type="button"
             onClick={onClose}
+            aria-label={t('common.close')}
             className="p-2 rounded-lg hover:bg-th-hover text-th-text-s transition-colors"
           >
             <X size={20} />