diff --git a/web/experience/src/components/AnnouncementCard.tsx b/web/experience/src/components/AnnouncementCard.tsx
index 7ec4c8a..4c6a746 100644
--- a/web/experience/src/components/AnnouncementCard.tsx
+++ b/web/experience/src/components/AnnouncementCard.tsx
@@ -33,10 +33,12 @@ export const AnnouncementCard: React.FC<AnnouncementCardProps> = ({
     };
 
     return (
-        <div className={`relative p-6 rounded-2xl border transition-all duration-300 ${announcement.is_pinned
+        <article
+            aria-labelledby={`ann-title-${announcement.id}`}
+            className={`relative p-6 rounded-2xl border transition-all duration-300 ${announcement.is_pinned
                 ? 'bg-primary-500/10 border-primary-500/30'
                 : 'bg-white/5 border-white/10 hover:border-white/20'
-            }`}>
+                }`}>
             {announcement.is_pinned && (
                 <div className="absolute top-4 right-4 text-primary-400">
                     <Pin className="w-4 h-4 fill-current" />
@@ -67,17 +69,18 @@ export const AnnouncementCard: React.FC<AnnouncementCardProps> = ({
                             disabled={isDeleting}
                             className="p-2 rounded-lg hover:bg-red-500/20 text-gray-400 hover:text-red-400 transition-colors"
                             title="Eliminar anuncio"
+                            aria-label="Eliminar anuncio"
                         >
-                            <Trash2 className="w-4 h-4" />
+                            <Trash2 className="w-4 h-4" aria-hidden="true" />
                         </button>
                     </div>
                 )}
             </div>
 
-            <h3 className="text-xl font-bold text-white mb-2">{announcement.title}</h3>
+            <h3 id={`ann-title-${announcement.id}`} className="text-xl font-bold text-white mb-2">{announcement.title}</h3>
             <div className="text-gray-300 whitespace-pre-wrap leading-relaxed">
                 {announcement.content}
             </div>
-        </div>
+        </article>
     );
 };
diff --git a/web/experience/src/components/AppHeader.tsx b/web/experience/src/components/AppHeader.tsx
index 524f725..383cb40 100644
--- a/web/experience/src/components/AppHeader.tsx
+++ b/web/experience/src/components/AppHeader.tsx
@@ -25,14 +25,14 @@ export default function AppHeader() {
             <Link href="/" className="flex items-center gap-2 md:gap-3 group" aria-label={`${platformName} - Dashboard`}>
                 <div className="w-8 h-8 md:w-10 md:h-10 rounded-lg md:rounded-xl bg-blue-600 flex items-center justify-center font-black text-white shadow-lg shadow-blue-500/20 group-hover:scale-105 transition-all overflow-hidden relative">
                     {branding?.logo_url ? (
-                        <Image src={getImageUrl(branding.logo_url)} alt={branding.name} fill className="object-contain" sizes="40px" />
+                        <Image src={getImageUrl(branding.logo_url)} alt="" fill className="object-contain" sizes="40px" />
                     ) : (
                         <div className="absolute inset-0 flex items-center justify-center bg-gradient-to-br from-blue-500 to-blue-700" aria-hidden="true">
                             {platformName.charAt(0).toUpperCase()}
                         </div>
                     )}
                 </div>
-                <div className="flex flex-col -gap-1">
+                <div className="flex flex-col -gap-1" aria-hidden="true">
                     <span className="font-black text-sm md:text-lg tracking-tighter text-white leading-none">
                         {platformName.toUpperCase()}
                     </span>
@@ -41,7 +41,7 @@ export default function AppHeader() {
             </Link>
 
             <div className="flex items-center gap-4">
-                <nav className="hidden md:flex items-center gap-8 mr-4">
+                <nav className="hidden md:flex items-center gap-8 mr-4" aria-label="Navegación principal">
                     <Link href="/" className="text-[10px] font-black uppercase tracking-[0.2em] text-gray-400 hover:text-white transition-colors">
                         {t('nav.catalog')}
                     </Link>
@@ -106,8 +106,17 @@ export default function AppHeader() {
 
             {/* Mobile Sidebar Overlay */}
             {isMenuOpen && (
-                <div className="fixed inset-0 z-[150] md:hidden bg-black/60 backdrop-blur-sm animate-in fade-in duration-300">
-                    <div className="absolute right-0 top-0 bottom-0 w-64 glass border-l border-white/10 p-6 flex flex-col animate-in slide-in-from-right duration-300">
+                <div
+                    className="fixed inset-0 z-[150] md:hidden bg-black/60 backdrop-blur-sm animate-in fade-in duration-300"
+                    onClick={() => setIsMenuOpen(false)}
+                >
+                    <div
+                        className="absolute right-0 top-0 bottom-0 w-64 glass border-l border-white/10 p-6 flex flex-col animate-in slide-in-from-right duration-300"
+                        role="dialog"
+                        aria-modal="true"
+                        aria-label="Menú móvil"
+                        onClick={(e) => e.stopPropagation()}
+                    >
                         <div className="flex justify-between items-center mb-8">
                             <span className="font-black text-xs uppercase tracking-[0.2em] text-gray-500">Menú</span>
                             <button
@@ -119,7 +128,7 @@ export default function AppHeader() {
                             </button>
                         </div>
 
-                        <nav className="flex flex-col gap-6 flex-1">
+                        <nav className="flex flex-col gap-6 flex-1" aria-label="Mobile navigation">
                             <Link
                                 href="/"
                                 onClick={() => setIsMenuOpen(false)}
@@ -175,7 +184,7 @@ export default function AppHeader() {
                                 onClick={() => setIsMenuOpen(false)}
                                 className="flex items-center gap-3 px-4 py-3 rounded-xl hover:bg-white/5 transition-colors"
                             >
-                                <div className="w-8 h-8 rounded-full bg-blue-500/20 flex items-center justify-center font-bold text-xs text-blue-400">
+                                <div className="w-8 h-8 rounded-full bg-blue-500/20 flex items-center justify-center font-bold text-xs text-blue-400" aria-hidden="true">
                                     {user?.full_name?.charAt(0) || 'U'}
                                 </div>
                                 <span className="text-sm font-bold">{user?.full_name || 'Mi Perfil'}</span>
@@ -184,7 +193,7 @@ export default function AppHeader() {
                                 onClick={logout}
                                 className="w-full flex items-center gap-3 px-4 py-3 rounded-xl text-red-400 hover:bg-red-500/10 transition-colors"
                             >
-                                <LogOut size={18} />
+                                <LogOut size={18} aria-hidden="true" />
                                 <span className="text-sm font-bold">{t('nav.signOut')}</span>
                             </button>
                         </div>
diff --git a/web/experience/src/components/InteractiveTranscript.tsx b/web/experience/src/components/InteractiveTranscript.tsx
index 4207524..e9fdad9 100644
--- a/web/experience/src/components/InteractiveTranscript.tsx
+++ b/web/experience/src/components/InteractiveTranscript.tsx
@@ -56,12 +56,14 @@ export default function InteractiveTranscript({ transcription, currentTime, onSe
                 <div className="flex bg-black/40 rounded-lg p-1 border border-white/5">
                     <button
                         onClick={() => setLang('en')}
+                        aria-pressed={lang === 'en'}
                         className={`px-3 py-1 text-[10px] font-black rounded-md transition-all ${lang === 'en' ? 'bg-blue-600 text-white' : 'text-gray-500 hover:text-white'}`}
                     >
                         EN
                     </button>
                     <button
                         onClick={() => setLang('es')}
+                        aria-pressed={lang === 'es'}
                         className={`px-3 py-1 text-[10px] font-black rounded-md transition-all ${lang === 'es' ? 'bg-blue-600 text-white' : 'text-gray-500 hover:text-white'}`}
                     >
                         ES
@@ -71,6 +73,9 @@ export default function InteractiveTranscript({ transcription, currentTime, onSe
 
             <div
                 ref={scrollRef}
+                role="region"
+                aria-label="Contenido de la transcripción"
+                aria-live="polite"
                 className="flex-1 overflow-y-auto p-6 space-y-4 custom-scrollbar"
             >
                 {cues.length === 0 ? (
@@ -88,14 +93,23 @@ export default function InteractiveTranscript({ transcription, currentTime, onSe
                             <div
                                 key={index}
                                 ref={active ? activeCueRef : null}
+                                role="button"
+                                tabIndex={0}
+                                aria-label={`${formatTime(cue.start)}: ${cue.text}`}
+                                aria-current={active ? "true" : undefined}
                                 onClick={() => onSeek(cue.start)}
+                                onKeyDown={(e) => {
+                                    if (e.key === 'Enter' || e.key === ' ') {
+                                        onSeek(cue.start);
+                                    }
+                                }}
                                 className={`group cursor-pointer p-4 rounded-2xl transition-all border ${active
                                     ? 'bg-blue-500/10 border-blue-500/30 text-white translate-x-1'
                                     : 'bg-white/5 border-transparent text-gray-400 hover:bg-white/10 hover:border-white/10'
                                     }`}
                             >
                                 <div className="flex items-start gap-4">
-                                    <span className={`text-[10px] font-mono mt-1 ${active ? 'text-blue-400' : 'text-gray-600'}`}>
+                                    <span className={`text-[10px] font-mono mt-1 ${active ? 'text-blue-400' : 'text-gray-600'}`} aria-hidden="true">
                                         {formatTime(cue.start)}
                                     </span>
                                     <p className={`text-sm leading-relaxed ${active ? 'font-medium' : ''}`}>
diff --git a/web/experience/src/components/Leaderboard.tsx b/web/experience/src/components/Leaderboard.tsx
index aadf325..70e38ec 100644
--- a/web/experience/src/components/Leaderboard.tsx
+++ b/web/experience/src/components/Leaderboard.tsx
@@ -2,7 +2,7 @@
 
 import { useEffect, useState } from "react";
 import { lmsApi, User } from "@/lib/api";
-import { Trophy, Medal, Award } from "lucide-react";
+import { Trophy, Medal } from "lucide-react";
 
 export default function Leaderboard() {
     const [topUsers, setTopUsers] = useState<User[]>([]);
@@ -33,21 +33,21 @@ export default function Leaderboard() {
     return (
         <div className="glass-card p-8 border-white/5 bg-white/[0.01] rounded-3xl overflow-hidden relative">
             <h3 className="text-xs font-black uppercase tracking-widest text-gray-500 mb-6 flex items-center gap-2">
-                <Trophy size={14} className="text-amber-500" /> Tabla de Clasificación
+                <Trophy size={14} className="text-amber-500" aria-hidden="true" /> Tabla de Clasificación
             </h3>
 
-            <div className="space-y-3">
+            <ol className="space-y-3" aria-label="Ranking de estudiantes">
                 {topUsers.map((user, index) => (
-                    <div
+                    <li
                         key={user.id}
                         className={`flex items-center gap-4 p-4 rounded-2xl transition-all ${index === 0 ? 'bg-gradient-to-r from-amber-500/10 to-transparent border border-amber-500/20 shadow-lg shadow-amber-500/5' :
-                                'bg-white/5 border border-white/5 hover:bg-white/10'
+                            'bg-white/5 border border-white/5 hover:bg-white/10'
                             }`}
                     >
-                        <div className="flex-shrink-0 w-8 text-center font-black text-xs text-gray-600">
-                            {index === 0 ? <Medal className="text-amber-500 mx-auto" size={18} /> :
-                                index === 1 ? <Medal className="text-gray-400 mx-auto" size={18} /> :
-                                    index === 2 ? <Medal className="text-amber-700 mx-auto" size={18} /> :
+                        <div className="flex-shrink-0 w-8 text-center font-black text-xs text-gray-600" aria-label={`Posición ${index + 1}`}>
+                            {index === 0 ? <Medal className="text-amber-500 mx-auto" size={18} aria-hidden="true" /> :
+                                index === 1 ? <Medal className="text-gray-400 mx-auto" size={18} aria-hidden="true" /> :
+                                    index === 2 ? <Medal className="text-amber-700 mx-auto" size={18} aria-hidden="true" /> :
                                         index + 1}
                         </div>
 
@@ -60,7 +60,7 @@ export default function Leaderboard() {
                             <div className="text-sm font-black text-white">{user.xp || 0}</div>
                             <div className="text-[8px] font-black text-blue-500 uppercase tracking-widest">XP</div>
                         </div>
-                    </div>
+                    </li>
                 ))}
 
                 {topUsers.length === 0 && (
@@ -68,10 +68,10 @@ export default function Leaderboard() {
                         Aún no hay datos de clasificación disponibles.
                     </div>
                 )}
-            </div>
+            </ol>
 
             {/* Visual background flair */}
-            <div className="absolute -top-24 -right-24 w-48 h-48 bg-amber-500/10 blur-[100px] rounded-full pointer-events-none"></div>
+            <div className="absolute -top-24 -right-24 w-48 h-48 bg-amber-500/10 blur-[100px] rounded-full pointer-events-none" aria-hidden="true"></div>
         </div>
     );
 }
diff --git a/web/experience/src/components/NewAnnouncementModal.tsx b/web/experience/src/components/NewAnnouncementModal.tsx
index 938004a..a6c073a 100644
--- a/web/experience/src/components/NewAnnouncementModal.tsx
+++ b/web/experience/src/components/NewAnnouncementModal.tsx
@@ -41,11 +41,18 @@ export const NewAnnouncementModal: React.FC<NewAnnouncementModalProps> = ({
     };
 
     return (
-        <div className="fixed inset-0 z-50 flex items-center justify-center p-4 bg-black/60 backdrop-blur-sm">
-            <div className="bg-[#1a1c1e] border border-white/10 rounded-3xl w-full max-w-2xl overflow-hidden shadow-2xl animate-in fade-in zoom-in duration-200">
+        <div className="fixed inset-0 z-50 flex items-center justify-center p-4 bg-black/60 backdrop-blur-sm"
+            onClick={onClose}>
+            <div
+                className="bg-[#1a1c1e] border border-white/10 rounded-3xl w-full max-w-2xl overflow-hidden shadow-2xl animate-in fade-in zoom-in duration-200"
+                role="dialog"
+                aria-modal="true"
+                aria-labelledby="modal-announcement-title"
+                onClick={(e) => e.stopPropagation()}
+            >
                 <div className="flex items-center justify-between p-6 border-b border-white/5">
-                    <h2 className="text-xl font-bold text-white flex items-center gap-2">
-                        <Send className="w-5 h-5 text-primary-500" />
+                    <h2 id="modal-announcement-title" className="text-xl font-bold text-white flex items-center gap-2">
+                        <Send className="w-5 h-5 text-primary-500" aria-hidden="true" />
                         Publicar Nuevo Anuncio
                     </h2>
                     <button onClick={onClose} className="p-2 hover:bg-white/5 rounded-xl text-gray-400 transition-colors">
@@ -62,20 +69,23 @@ export const NewAnnouncementModal: React.FC<NewAnnouncementModalProps> = ({
                     )}
 
                     <div className="space-y-2">
-                        <label className="text-sm font-medium text-gray-400 ml-1">Título del Anuncio</label>
+                        <label htmlFor="ann-title" className="text-sm font-medium text-gray-400 ml-1">Título del Anuncio</label>
                         <input
+                            id="ann-title"
                             type="text"
                             required
                             value={title}
                             onChange={(e) => setTitle(e.target.value)}
                             placeholder="Ej: Nuevos materiales disponibles"
                             className="w-full px-4 py-3 bg-white/5 border border-white/10 rounded-xl text-white placeholder:text-gray-500 focus:outline-none focus:border-primary-500/50 transition-colors"
+                            autoFocus
                         />
                     </div>
 
                     <div className="space-y-2">
-                        <label className="text-sm font-medium text-gray-400 ml-1">Contenido</label>
+                        <label htmlFor="ann-content" className="text-sm font-medium text-gray-400 ml-1">Contenido</label>
                         <textarea
+                            id="ann-content"
                             required
                             rows={6}
                             value={content}
diff --git a/web/experience/src/components/NewThreadModal.tsx b/web/experience/src/components/NewThreadModal.tsx
index 71e3971..0e4db08 100644
--- a/web/experience/src/components/NewThreadModal.tsx
+++ b/web/experience/src/components/NewThreadModal.tsx
@@ -46,10 +46,15 @@ export default function NewThreadModal({ courseId, lessonId, onClose, onSuccess
 
     return (
         <div className="fixed inset-0 bg-black/60 backdrop-blur-sm flex items-center justify-center p-4 z-50">
-            <div className="bg-slate-900 border border-white/10 rounded-3xl max-w-2xl w-full max-h-[90vh] overflow-y-auto shadow-2xl">
+            <div
+                className="bg-slate-900 border border-white/10 rounded-3xl max-w-2xl w-full max-h-[90vh] overflow-y-auto shadow-2xl"
+                role="dialog"
+                aria-modal="true"
+                aria-labelledby="modal-thread-title"
+            >
                 {/* Header */}
                 <div className="flex items-center justify-between p-6 border-b border-white/10">
-                    <h2 className="text-2xl font-black text-white">Nuevo Hilo de Discusión</h2>
+                    <h2 id="modal-thread-title" className="text-2xl font-black text-white">Nuevo Hilo de Discusión</h2>
                     <button
                         onClick={onClose}
                         className="w-10 h-10 rounded-full bg-white/5 hover:bg-white/10 flex items-center justify-center text-gray-400 hover:text-white transition-all"
@@ -68,10 +73,11 @@ export default function NewThreadModal({ courseId, lessonId, onClose, onSuccess
 
                     {/* Title */}
                     <div className="space-y-2">
-                        <label className="text-xs font-bold text-gray-400 uppercase tracking-wider">
+                        <label htmlFor="thread-title" className="text-xs font-bold text-gray-400 uppercase tracking-wider">
                             Título
                         </label>
                         <input
+                            id="thread-title"
                             type="text"
                             value={title}
                             onChange={(e) => setTitle(e.target.value)}
@@ -79,19 +85,21 @@ export default function NewThreadModal({ courseId, lessonId, onClose, onSuccess
                             className="w-full bg-slate-900/50 border border-white/10 rounded-xl py-3 px-4 text-white text-sm focus:border-indigo-500 focus:outline-none transition-colors"
                             disabled={submitting}
                             maxLength={200}
+                            autoFocus
                         />
-                        <p className="text-xs text-gray-500">{title.length}/200 caracteres</p>
+                        <p id="thread-title-hint" className="text-xs text-gray-500">{title.length}/200 caracteres</p>
                     </div>
 
                     {/* Content */}
                     <div className="space-y-2">
-                        <label className="text-xs font-bold text-gray-400 uppercase tracking-wider">
+                        <label htmlFor="thread-content" className="text-xs font-bold text-gray-400 uppercase tracking-wider">
                             Contenido
                         </label>
                         <textarea
+                            id="thread-content"
                             value={content}
                             onChange={(e) => setContent(e.target.value)}
-                            placeholder="Describe tu pregunta o tema en detalle..."
+                            placeholder="Describe tu pregunta o tema en detail..."
                             className="w-full bg-slate-900/50 border border-white/10 rounded-xl py-3 px-4 text-white text-sm focus:border-indigo-500 focus:outline-none transition-colors resize-none"
                             rows={8}
                             disabled={submitting}
diff --git a/web/experience/src/components/NotificationCenter.tsx b/web/experience/src/components/NotificationCenter.tsx
index 4e3a716..b71deb5 100644
--- a/web/experience/src/components/NotificationCenter.tsx
+++ b/web/experience/src/components/NotificationCenter.tsx
@@ -149,6 +149,7 @@ export default function NotificationCenter() {
                             <div className="p-4 border-t border-white/5 bg-white/5 text-center">
                                 <button
                                     className="text-[10px] font-black uppercase tracking-widest text-gray-500 hover:text-white transition-colors"
+                                    aria-label="Marcar todas las notificaciones como leídas"
                                     onClick={() => {
                                         notifications.filter(n => !n.is_read).forEach(n => markAsRead(n.id));
                                     }}
diff --git a/web/experience/src/components/PostCard.tsx b/web/experience/src/components/PostCard.tsx
index 3af3a49..df9ff79 100644
--- a/web/experience/src/components/PostCard.tsx
+++ b/web/experience/src/components/PostCard.tsx
@@ -32,14 +32,17 @@ export default function PostCard({ post, onReply, onVote, onEndorse, depth, isIn
     const indentClass = depth > 0 ? `ml-${Math.min(depth * 4, 16)} pl-4 border-l-2 border-white/10` : '';
 
     return (
-        <div className={`${indentClass} ${depth > 0 ? 'mt-4' : 'mt-6'}`}>
+        <article
+            className={`${indentClass} ${depth > 0 ? 'mt-4' : 'mt-6'}`}
+            aria-labelledby={`post-content-${post.id}`}
+        >
             <div className="bg-white/5 backdrop-blur-xl border border-white/10 rounded-2xl p-4 hover:bg-white/[0.07] transition-all">
                 {/* Header */}
                 <div className="flex items-start gap-3 mb-3">
                     {/* Avatar */}
-                    <div className="w-10 h-10 rounded-full bg-indigo-600/20 flex items-center justify-center text-indigo-400 flex-shrink-0">
+                    <div className="w-10 h-10 rounded-full bg-indigo-600/20 flex items-center justify-center text-indigo-400 flex-shrink-0" aria-hidden="true">
                         {post.author_avatar ? (
-                            <img src={post.author_avatar} alt={post.author_name} className="w-full h-full rounded-full object-cover" />
+                            <img src={post.author_avatar} alt="" className="w-full h-full rounded-full object-cover" />
                         ) : (
                             <User size={20} />
                         )}
@@ -63,7 +66,7 @@ export default function PostCard({ post, onReply, onVote, onEndorse, depth, isIn
                 </div>
 
                 {/* Content */}
-                <div className="text-gray-300 text-sm mb-4 whitespace-pre-wrap break-words">
+                <div id={`post-content-${post.id}`} className="text-gray-300 text-sm mb-4 whitespace-pre-wrap break-words">
                     {post.content}
                 </div>
 
@@ -73,12 +76,14 @@ export default function PostCard({ post, onReply, onVote, onEndorse, depth, isIn
                     <button
                         onClick={() => handleVote('upvote')}
                         disabled={isVoting}
+                        aria-label={`Votar positivo (${post.upvotes} votos)`}
+                        aria-pressed={post.user_vote === 'upvote'}
                         className={`flex items-center gap-1.5 px-3 py-1.5 rounded-lg transition-all ${post.user_vote === 'upvote'
-                                ? 'bg-indigo-600/30 text-indigo-400 border border-indigo-500/50'
-                                : 'bg-white/5 text-gray-400 hover:bg-white/10 hover:text-white border border-white/10'
+                            ? 'bg-indigo-600/30 text-indigo-400 border border-indigo-500/50'
+                            : 'bg-white/5 text-gray-400 hover:bg-white/10 hover:text-white border border-white/10'
                             } disabled:opacity-50`}
                     >
-                        <ThumbsUp size={14} />
+                        <ThumbsUp size={14} aria-hidden="true" />
                         <span className="font-bold">{post.upvotes}</span>
                     </button>
 
@@ -86,9 +91,10 @@ export default function PostCard({ post, onReply, onVote, onEndorse, depth, isIn
                     {depth < maxDepth && (
                         <button
                             onClick={() => onReply(post.id)}
+                            aria-label={`Responder al post de ${post.author_name}`}
                             className="flex items-center gap-1.5 px-3 py-1.5 rounded-lg bg-white/5 text-gray-400 hover:bg-white/10 hover:text-white border border-white/10 transition-all"
                         >
-                            <MessageSquare size={14} />
+                            <MessageSquare size={14} aria-hidden="true" />
                             <span className="font-bold">Responder</span>
                         </button>
                     )}
@@ -97,12 +103,14 @@ export default function PostCard({ post, onReply, onVote, onEndorse, depth, isIn
                     {isInstructor && onEndorse && (
                         <button
                             onClick={() => onEndorse(post.id)}
+                            aria-label={post.is_endorsed ? 'Quitar aprobación de respuesta' : 'Marcar como respuesta correcta'}
+                            aria-pressed={!!post.is_endorsed}
                             className={`flex items-center gap-1.5 px-3 py-1.5 rounded-lg transition-all ${post.is_endorsed
-                                    ? 'bg-green-600/30 text-green-400 border border-green-500/50'
-                                    : 'bg-white/5 text-gray-400 hover:bg-green-600/20 hover:text-green-400 border border-white/10'
+                                ? 'bg-green-600/30 text-green-400 border border-green-500/50'
+                                : 'bg-white/5 text-gray-400 hover:bg-green-600/20 hover:text-green-400 border border-white/10'
                                 }`}
                         >
-                            <CheckCircle2 size={14} />
+                            <CheckCircle2 size={14} aria-hidden="true" />
                             <span className="font-bold text-xs">{post.is_endorsed ? 'Aprobada' : 'Aprobar'}</span>
                         </button>
                     )}
@@ -125,6 +133,6 @@ export default function PostCard({ post, onReply, onVote, onEndorse, depth, isIn
                     ))}
                 </div>
             )}
-        </div>
+        </article>
     );
 }
diff --git a/web/studio/src/components/Modal.tsx b/web/studio/src/components/Modal.tsx
index 8379dfc..879f988 100644
--- a/web/studio/src/components/Modal.tsx
+++ b/web/studio/src/components/Modal.tsx
@@ -35,17 +35,20 @@ export default function Modal({ isOpen, onClose, title, children }: ModalProps)
         <div className="fixed inset-0 z-[100] flex items-center justify-center p-4 bg-black/60 backdrop-blur-sm animate-in fade-in duration-200">
             <div
                 ref={modalRef}
+                role="dialog"
+                aria-modal="true"
+                aria-labelledby="modal-title"
                 className="w-full max-w-md glass-card bg-[#1a1d23] border border-white/10 rounded-2xl p-8 shadow-2xl animate-in zoom-in-95 duration-200"
             >
                 <div className="flex justify-between items-center mb-6">
-                    <h2 className="text-xl font-bold bg-gradient-to-r from-white to-gray-400 bg-clip-text text-transparent italic">
+                    <h2 id="modal-title" className="text-xl font-bold bg-gradient-to-r from-white to-gray-400 bg-clip-text text-transparent italic">
                         {title}
                     </h2>
                     <button
                         onClick={onClose}
                         className="p-2 hover:bg-white/5 rounded-full transition-colors text-gray-400 hover:text-white"
                     >
-                        <X size={20} />
+                        <X size={20} aria-hidden="true" />
                     </button>
                 </div>
                 {children}