diff --git a/css/styles.css b/css/styles.css
index c2bfb2f..4601e34 100644
--- a/css/styles.css
+++ b/css/styles.css
@@ -5,6 +5,19 @@
     box-sizing: border-box;
 }
 
+/* Accessibilité - Classes utilitaires */
+.sr-only {
+    position: absolute !important;
+    width: 1px !important;
+    height: 1px !important;
+    padding: 0 !important;
+    margin: -1px !important;
+    overflow: hidden !important;
+    clip: rect(0, 0, 0, 0) !important;
+    white-space: nowrap !important;
+    border: 0 !important;
+}
+
 :root {
     --primary-red: #FF0000;
     --primary-green: #008000;
@@ -42,6 +55,38 @@ a {
     color: var(--text-color);
 }
 
+/* Amélioration du focus pour l'accessibilité */
+a:focus,
+button:focus,
+input:focus,
+textarea:focus,
+select:focus {
+    outline: 2px solid var(--primary-red);
+    outline-offset: 2px;
+    border-radius: 2px;
+}
+
+/* Support pour les préférences d'animation réduite */
+@media (prefers-reduced-motion: reduce) {
+    *, *::before, *::after {
+        animation-duration: 0.01ms !important;
+        animation-iteration-count: 1 !important;
+        transition-duration: 0.01ms !important;
+    }
+}
+
+/* Support pour le contraste élevé */
+@media (prefers-contrast: high) {
+    :root {
+        --text-color: #000000;
+        --primary-red: #CC0000;
+        --card-bg: #FFFFFF;
+        --sidebar-bg: #F0F0F0;
+        --tag-bg: #E8E8E8;
+        --search-bg: #D0D0D0;
+    }
+}
+
 img {
     max-width: 100%;
     height: auto;
diff --git a/includes/header.php b/includes/header.php
index e9d3747..c1e18da 100644
--- a/includes/header.php
+++ b/includes/header.php
@@ -1,38 +1,50 @@
 <!-- Header avec barre de recherche et icônes -->
-<div class="header">
+<header class="header" role="banner">
     <div class="search-container">
-        <form action="recherche.php" method="get">
-            <input type="text" name="q" placeholder="Rechercher...">
-            <button type="submit"><i class="fas fa-search"></i></button>
+        <form action="recherche.php" method="get" role="search" aria-label="Recherche de vidéos">
+            <label for="search-input" class="sr-only">Rechercher des vidéos</label>
+            <input type="text" id="search-input" name="q" placeholder="Rechercher..." aria-describedby="search-help">
+            <button type="submit" aria-label="Lancer la recherche">
+                <i class="fas fa-search" aria-hidden="true"></i>
+            </button>
+            <div id="search-help" class="sr-only">Tapez vos mots-clés pour rechercher des vidéos</div>
         </form>
     </div>
 
-    <div class="social-icons">
-        <a target="_blank" rel="me noreferrer" href="<?php echo MASTODON_URL; ?>" class="icon-button"><i class="fab fa-mastodon icon-mastodon"></i></a>
-        <a target="_blank" rel="noreferrer" href="<?php echo INSTAGRAM_URL; ?>" class="icon-button"><i class="fab fa-instagram icon-instagram"></i></a>
-        <a target="_blank" rel="noreferrer" href="<?php echo TIKTOK_URL; ?>" class="icon-button"><i class="fab fa-tiktok icon-tiktok"></i></a>
+    <nav class="social-icons" aria-label="Réseaux sociaux">
+        <a target="_blank" rel="me noreferrer" href="<?php echo MASTODON_URL; ?>" class="icon-button" aria-label="Suivre sur Mastodon">
+            <i class="fab fa-mastodon icon-mastodon" aria-hidden="true"></i>
+        </a>
+        <a target="_blank" rel="noreferrer" href="<?php echo INSTAGRAM_URL; ?>" class="icon-button" aria-label="Suivre sur Instagram">
+            <i class="fab fa-instagram icon-instagram" aria-hidden="true"></i>
+        </a>
+        <a target="_blank" rel="noreferrer" href="<?php echo TIKTOK_URL; ?>" class="icon-button" aria-label="Suivre sur TikTok">
+            <i class="fab fa-tiktok icon-tiktok" aria-hidden="true"></i>
+        </a>
         <div class="more-social-container">
-            <a href="#" class="icon-button more-social-toggle"><i class="fas fa-ellipsis-h"></i></a>
-            <div class="more-social-dropdown">
-                <a target="_blank" rel="noreferrer" href="<?php echo FACEBOOK_URL; ?>" class="more-social-item">
-                    <i class="fab fa-facebook icon-facebook"></i> Facebook
+            <button type="button" class="icon-button more-social-toggle" aria-expanded="false" aria-controls="social-dropdown" aria-label="Voir plus de réseaux sociaux">
+                <i class="fas fa-ellipsis-h" aria-hidden="true"></i>
+            </button>
+            <div id="social-dropdown" class="more-social-dropdown" role="menu">
+                <a target="_blank" rel="noreferrer" href="<?php echo FACEBOOK_URL; ?>" class="more-social-item" role="menuitem">
+                    <i class="fab fa-facebook icon-facebook" aria-hidden="true"></i> Facebook
                 </a>
-                <a target="_blank" rel="noreferrer" href="<?php echo YOUTUBE_URL; ?>" class="more-social-item">
-                    <i class="fab fa-youtube icon-youtube"></i> YouTube
+                <a target="_blank" rel="noreferrer" href="<?php echo YOUTUBE_URL; ?>" class="more-social-item" role="menuitem">
+                    <i class="fab fa-youtube icon-youtube" aria-hidden="true"></i> YouTube
                 </a>
-                <a target="_blank" rel="noreferrer" href="<?php echo X_URL; ?>" class="more-social-item">
-                    <i class="fab fa-x-twitter icon-x"></i> X
+                <a target="_blank" rel="noreferrer" href="<?php echo X_URL; ?>" class="more-social-item" role="menuitem">
+                    <i class="fab fa-x-twitter icon-x" aria-hidden="true"></i> X
                 </a>
             </div>
         </div>
-    </div>
+    </nav>
 
     <div class="action-icons">
-        <button id="install-pwa" class="icon-button install-pwa-button" style="display: none;" title="Installer l'application">
-            <i class="fas fa-download"></i>
+        <button id="install-pwa" class="icon-button install-pwa-button" style="display: none;" aria-label="Installer l'application">
+            <i class="fas fa-download" aria-hidden="true"></i>
         </button>
-        <button class="mobile-menu-toggle">
-            <i class="fas fa-bars"></i>
+        <button class="mobile-menu-toggle" aria-expanded="false" aria-controls="mobile-menu" aria-label="Ouvrir le menu de navigation">
+            <i class="fas fa-bars" aria-hidden="true"></i>
         </button>
     </div>
-</div>
+</header>
diff --git a/includes/sidebar.php b/includes/sidebar.php
index 8c61aa6..5e9133b 100644
--- a/includes/sidebar.php
+++ b/includes/sidebar.php
@@ -1,7 +1,7 @@
 <!-- Sidebar de navigation -->
-<div class="sidebar">
-    <a href="/" class="logo">
-        <img src="img/logo.png" alt="kaubuntu.re">
+<nav class="sidebar" role="navigation" aria-label="Navigation principale">
+    <a href="/" class="logo" aria-label="Retour à l'accueil">
+        <img src="img/logo.png" alt="Logo kaubuntu.re">
     </a>
 
     <?php
@@ -13,12 +13,12 @@
     $currentTag = $isTagSearch ? substr($currentQuery, 1) : '';
     ?>
 
-    <nav class="sidebar-nav">
-        <a href="/" class="nav-item <?php echo ($currentPage === 'index.php') ? 'active' : ''; ?>" data-title="Accueil">
-            <i class="fas fa-home"></i> <span>Accueil</span>
+    <div class="sidebar-nav">
+        <a href="/" class="nav-item <?php echo ($currentPage === 'index.php') ? 'active' : ''; ?>" data-title="Accueil" aria-current="<?php echo ($currentPage === 'index.php') ? 'page' : 'false'; ?>">
+            <i class="fas fa-home" aria-hidden="true"></i> <span>Accueil</span>
         </a>
-        <a href="direct.php" class="nav-item <?php echo ($currentPage === 'direct.php') ? 'active' : ''; ?>" data-title="Direct">
-            <i class="fas fa-broadcast-tower"></i> <span>Direct</span>
+        <a href="direct.php" class="nav-item <?php echo ($currentPage === 'direct.php') ? 'active' : ''; ?>" data-title="Direct" aria-current="<?php echo ($currentPage === 'direct.php') ? 'page' : 'false'; ?>">
+            <i class="fas fa-broadcast-tower" aria-hidden="true"></i> <span>Direct</span>
         </a>
 
         <div class="nav-divider"></div>
@@ -51,8 +51,8 @@
             foreach (PRIORITY_CATEGORIES as $id => $name) {
                 $isActive = ($currentPage === 'categories.php' && $currentCategoryId === $id);
                 $icon = isset($categoryIcons[$id]) ? $categoryIcons[$id] : 'fas fa-folder';
-                echo '<a href="categories.php?id=' . $id . '" class="nav-item ' . ($isActive ? 'active' : '') . '" data-title="' . htmlspecialchars($name) . '">';
-                echo '<i class="' . $icon . '"></i> <span>' . htmlspecialchars($name) . '</span>';
+                echo '<a href="categories.php?id=' . $id . '" class="nav-item ' . ($isActive ? 'active' : '') . '" data-title="' . htmlspecialchars($name) . '" aria-current="' . ($isActive ? 'page' : 'false') . '">';
+                echo '<i class="' . $icon . '" aria-hidden="true"></i> <span>' . htmlspecialchars($name) . '</span>';
                 echo '</a>';
             }
         }
@@ -60,8 +60,8 @@
 
         <div class="nav-divider"></div>
 
-        <div class="category-title">
-            <i class="fas fa-hashtag"></i> <span>Hashtags</span>
+        <div class="category-title" role="heading" aria-level="2">
+            <i class="fas fa-hashtag" aria-hidden="true"></i> <span>Hashtags</span>
         </div>
 
         <?php
@@ -70,12 +70,12 @@
                 $encodedTag = urlencode('#' . $tag);
                 $isActive = ($isTagSearch && strtolower($currentTag) === strtolower($tag));
         ?>
-        <a href="recherche.php?q=<?php echo $encodedTag; ?>" class="tag-item <?php echo $isActive ? 'active' : ''; ?>" data-title="<?php echo htmlspecialchars($tag); ?>">
-            <i class="fas fa-hashtag tag-icon"></i> <span><?php echo htmlspecialchars($tag); ?></span>
+        <a href="recherche.php?q=<?php echo $encodedTag; ?>" class="tag-item <?php echo $isActive ? 'active' : ''; ?>" data-title="<?php echo htmlspecialchars($tag); ?>" aria-current="<?php echo $isActive ? 'page' : 'false'; ?>">
+            <i class="fas fa-hashtag tag-icon" aria-hidden="true"></i> <span><?php echo htmlspecialchars($tag); ?></span>
         </a>
         <?php
             endforeach;
         endif;
         ?>
-    </nav>
-</div>
+    </div>
+</nav>
diff --git a/index.php b/index.php
index b27ccd5..d61b533 100644
--- a/index.php
+++ b/index.php
@@ -65,12 +65,13 @@ setSecurityHeaders();
 <body>
     <?php include 'includes/sidebar.php'; ?>
     <!-- Contenu principal -->
-    <div class="main-content">
+    <main class="main-content" id="main-content" role="main">
         <?php include 'includes/header.php'; ?>
         <!-- Hero and Mastodon container -->
         <div class="hero-mastodon-wrapper">
             <!-- Hero Banner -->
-            <div class="hero">
+            <section class="hero" aria-labelledby="live-section-title">
+                <h2 id="live-section-title" class="sr-only">Diffusion en direct</h2>
                 <?php
                 // Vérifier s'il y a un direct en cours
                 $liveStream = getLiveStream();
@@ -87,20 +88,24 @@ setSecurityHeaders();
                             frameborder="0"
                             allowfullscreen="allowfullscreen"
                             allow="autoplay; fullscreen"
-                            title="<?php echo htmlspecialchars($liveStream['title']); ?>">
+                            title="Diffusion en direct: <?php echo htmlspecialchars($liveStream['title']); ?>"
+                            aria-describedby="live-description">
                         </iframe>
+                        <div id="live-description" class="sr-only">
+                            Lecteur vidéo pour la diffusion en direct de <?php echo htmlspecialchars($liveStream['channel']); ?>
+                        </div>
                     </div>
                     <div class="hero-video-info">
                         <h2><?php echo htmlspecialchars($liveStream['title']); ?></h2>
                         <div class="hero-channel-info">
                             <?php if (strpos($liveStream['channelAvatar'], 'default-avatar.png') !== false || empty($liveStream['channelAvatar'])): ?>
-                                <div class="channel-avatar-placeholder">
-                                    <i class="fas fa-user-circle"></i>
+                                <div class="channel-avatar-placeholder" role="img" aria-label="Avatar par défaut">
+                                    <i class="fas fa-user-circle" aria-hidden="true"></i>
                                 </div>
                             <?php else: ?>
-                                <img src="<?php echo $liveStream['channelAvatar']; ?>" alt="<?php echo $liveStream['channel']; ?>" class="channel-avatar">
+                                <img src="<?php echo $liveStream['channelAvatar']; ?>" alt="Avatar de la chaîne <?php echo htmlspecialchars($liveStream['channel']); ?>" class="channel-avatar">
                             <?php endif; ?>
-                            <span class="channel-name"><?php echo $liveStream['channel']; ?></span>
+                            <span class="channel-name"><?php echo htmlspecialchars($liveStream['channel']); ?></span>
                         </div>
                     </div>
                 <?php
@@ -115,7 +120,7 @@ setSecurityHeaders();
                 <?php
                 }
                 ?>
-            </div>
+            </section>
 
             <div id="mt-container" class="mt-container">
                 <div class="mt-header">
@@ -146,12 +151,12 @@ setSecurityHeaders();
         <hr class="section-divider">
 
         <!-- Section Shorts -->
-        <div class="video-section">
+        <section class="video-section" aria-labelledby="shorts-heading">
             <div class="section-header">
                 <div class="section-logo">
-                    <img src="img/logo.png" alt="kaubuntu.re">
+                    <img src="img/logo.png" alt="Logo kaubuntu.re" aria-hidden="true">
                 </div>
-                <h2 class="section-title">Shorts</h2>
+                <h2 id="shorts-heading" class="section-title">Shorts</h2>
             </div>
 
             <div class="carousel">
@@ -167,7 +172,7 @@ setSecurityHeaders();
                         foreach ($shorts as $video):
                     ?>
                     <div class="carousel-item">
-                        <div class="video-card" data-video-id="<?php echo $video['id']; ?>">
+                        <article class="video-card" data-video-id="<?php echo $video['id']; ?>">
                             <div class="video-thumbnail">
                                 <img src="<?php echo $video['thumbnail']; ?>" alt="<?php echo $video['title']; ?>">
                                 <div class="video-play-icon">
@@ -190,19 +195,19 @@ setSecurityHeaders();
                 </div>
                 <?php endif; ?>
             </div>
-        </div>
+        </section>
 
         <!-- Séparateur stylisé -->
         <hr class="section-divider">
 
         <!-- Section Dernières vidéos -->
-        <div class="video-section">
-            <div class="section-header">
+        <section class="video-section" aria-labelledby="recent-videos-heading">
+            <header class="section-header">
                 <div class="section-logo">
-                    <img src="img/logo.png" alt="kaubuntu.re">
+                    <img src="img/logo.png" alt="Logo kaubuntu.re" aria-hidden="true">
                 </div>
-                <h2 class="section-title">Dernières vidéos</h2>
-            </div>
+                <h2 id="recent-videos-heading" class="section-title">Dernières vidéos</h2>
+            </header>
 
             <div class="video-grid">
                 <?php
@@ -215,16 +220,18 @@ setSecurityHeaders();
                 } else {
                     foreach ($recentVideos as $video):
                 ?>
-                <div class="video-card" data-video-id="<?php echo $video['id']; ?>">
+                <article class="video-card" data-video-id="<?php echo $video['id']; ?>">
                     <div class="video-thumbnail">
-                        <img src="<?php echo $video['thumbnail']; ?>" alt="<?php echo $video['title']; ?>">
-                        <div class="video-play-icon">
+                        <img src="<?php echo $video['thumbnail']; ?>" alt="Miniature de la vidéo: <?php echo htmlspecialchars($video['title']); ?>">
+                        <div class="video-play-icon" aria-hidden="true">
                             <i class="fas fa-play-circle"></i>
                         </div>
-                        <div class="video-duration"><?php echo formatDuration($video['duration']); ?></div>
+                        <div class="video-duration" aria-label="Durée: <?php echo formatDuration($video['duration']); ?>">
+                            <?php echo formatDuration($video['duration']); ?>
+                        </div>
                     </div>
                     <div class="video-info">
-                        <h3 class="video-title"><?php echo $video['title']; ?></h3>
+                        <h3 class="video-title"><?php echo htmlspecialchars($video['title']); ?></h3>
                         <div class="video-channel">
                             <?php if (strpos($video['channelAvatar'], 'default-avatar.png') !== false || empty($video['channelAvatar'])): ?>
                                 <div class="channel-avatar-placeholder">
@@ -240,7 +247,7 @@ setSecurityHeaders();
                             <span class="video-date"><i class="far fa-calendar-alt"></i> <?php echo formatDate($video['date']); ?></span>
                         </div>
                     </div>
-                </div>
+                </article>
                 <?php
                     endforeach;
                 }
@@ -248,19 +255,19 @@ setSecurityHeaders();
             </div>
 
             <button class="view-more">Voir plus</button>
-        </div>
+        </section>
 
         <!-- Séparateur stylisé -->
         <hr class="section-divider">
 
         <!-- Section Tendances -->
-        <div class="video-section">
-            <div class="section-header">
+        <section class="video-section" aria-labelledby="trending-videos-heading">
+            <header class="section-header">
                 <div class="section-logo">
-                    <img src="img/logo.png" alt="kaubuntu.re">
+                    <img src="img/logo.png" alt="Logo kaubuntu.re" aria-hidden="true">
                 </div>
-                <h2 class="section-title">Tendances</h2>
-            </div>
+                <h2 id="trending-videos-heading" class="section-title">Tendances</h2>
+            </header>
 
             <div class="video-grid">
                 <?php
@@ -273,7 +280,7 @@ setSecurityHeaders();
                 } else {
                     foreach ($trendingVideos as $video):
                 ?>
-                <div class="video-card" data-video-id="<?php echo $video['id']; ?>">
+                <article class="video-card" data-video-id="<?php echo $video['id']; ?>">
                     <div class="video-thumbnail">
                         <img src="<?php echo $video['thumbnail']; ?>" alt="<?php echo $video['title']; ?>">
                         <div class="video-play-icon">
@@ -298,7 +305,7 @@ setSecurityHeaders();
                             <span class="video-date"><i class="far fa-calendar-alt"></i> <?php echo formatDate($video['date']); ?></span>
                         </div>
                     </div>
-                </div>
+                </article>
                 <?php
                     endforeach;
                 }
@@ -306,7 +313,7 @@ setSecurityHeaders();
             </div>
 
             <button class="view-more">Voir plus</button>
-        </div>
+        </section>
 
         <!-- Séparateur stylisé -->
         <hr class="section-divider">
@@ -321,17 +328,17 @@ setSecurityHeaders();
             if (!empty($category['videos'])):
         ?>
         <!-- Section Catégorie: <?php echo $category['name']; ?> -->
-        <div class="video-section" data-category-id="<?php echo $category['id']; ?>">
-            <div class="section-header">
+        <section class="video-section" data-category-id="<?php echo $category['id']; ?>" aria-labelledby="category-heading-<?php echo $category['id']; ?>">
+            <header class="section-header">
                 <div class="section-logo">
-                    <img src="img/logo.png" alt="kaubuntu.re">
+                    <img src="img/logo.png" alt="Logo kaubuntu.re" aria-hidden="true">
                 </div>
-                <h2 class="section-title"><?php echo $category['name']; ?></h2>
-            </div>
+                <h2 id="category-heading-<?php echo $category['id']; ?>" class="section-title"><?php echo htmlspecialchars($category['name']); ?></h2>
+            </header>
 
             <div class="video-grid">
                 <?php foreach ($category['videos'] as $video): ?>
-                <div class="video-card" data-video-id="<?php echo $video['id']; ?>">
+                <article class="video-card" data-video-id="<?php echo $video['id']; ?>">
                     <div class="video-thumbnail">
                         <img src="<?php echo $video['thumbnail']; ?>" alt="<?php echo $video['title']; ?>">
                         <div class="video-play-icon">
@@ -356,12 +363,12 @@ setSecurityHeaders();
                             <span class="video-date"><i class="far fa-calendar-alt"></i> <?php echo formatDate($video['date']); ?></span>
                         </div>
                     </div>
-                </div>
+                </article>
                 <?php endforeach; ?>
             </div>
 
             <button class="view-more">Voir plus</button>
-        </div>
+        </section>
 
         <!-- Séparateur stylisé -->
         <hr class="section-divider">
@@ -372,10 +379,10 @@ setSecurityHeaders();
         ?>
 
         <!-- Section Flexbox pour Informations et Tendances Hashtags -->
-        <div class="info-tags-container">
+        <section class="info-tags-container">
             <?php if (defined('MOVEMENT_DESCRIPTION') && !empty(MOVEMENT_DESCRIPTION)): ?>
             <!-- Section Informations -->
-            <div class="info-section">
+            <article class="info-section">
                 <h2 class="info-header"><?php echo MOVEMENT_DESCRIPTION; ?></h2>
 
                 <?php if (defined('MOVEMENT_IMAGE') && !empty(MOVEMENT_IMAGE)): ?>
@@ -388,12 +395,12 @@ setSecurityHeaders();
                     <?php endif; ?>
                 </figure>
                 <?php endif; ?>
-            </div>
+            </article>
             <?php endif; ?>
 
             <!-- Section Tendances Hashtags -->
-            <div class="tags-section-container">
-                <h2 class="section-title centered">Tendances</h2>
+            <aside class="tags-section-container" aria-labelledby="hashtags-heading">
+                <h2 id="hashtags-heading" class="section-title centered">Tendances</h2>
 
                 <div class="tags-section">
                     <?php
@@ -407,9 +414,9 @@ setSecurityHeaders();
                     endif;
                     ?>
                 </div>
-            </div>
-        </div>
-    </div>
+            </aside>
+        </section>
+    </main>
     <?php include 'includes/footer.php'; ?>
     <?php include 'includes/mobile-menu.php'; ?>
     <script src="js/main.js"></script>
diff --git a/video.php b/video.php
index 6fcd0c3..bb70da6 100644
--- a/video.php
+++ b/video.php
@@ -162,52 +162,58 @@ if (empty($videoData) || isset($videoData['error'])) {
     <?php include 'includes/sidebar.php'; ?>
     
     <!-- Contenu principal -->
-    <div class="main-content">
+    <main class="main-content" id="main-content" role="main">
         <?php include 'includes/header.php'; ?>
         
         <?php if (isset($videoNotFound)): ?>
         <!-- Message d'erreur si la vidéo n'existe pas -->
-        <div class="error-message">
-            <i class="fas fa-exclamation-triangle"></i>
-            <h2>Vidéo non trouvée</h2>
+        <section class="error-message" role="alert" aria-labelledby="error-heading">
+            <i class="fas fa-exclamation-triangle" aria-hidden="true"></i>
+            <h1 id="error-heading">Vidéo non trouvée</h1>
             <p>La vidéo que vous recherchez n'existe pas ou a été supprimée.</p>
             <a href="index.php" class="btn-primary">Retour à l'accueil</a>
-        </div>
+        </section>
         
         <?php else: ?>
         <!-- Section vidéo -->
-        <div class="video-page">
-            <div class="video-player-container">
+        <article class="video-page" itemscope itemtype="https://schema.org/VideoObject">
+            <section class="video-player-container">
                 <div class="video-player">
-                    <iframe src="<?php echo htmlspecialchars($video['url']); ?>?warningTitle='0'" frameborder="0" allowfullscreen="allowfullscreen" allow="autoplay; fullscreen" title="<?php echo htmlspecialchars($video['title']); ?>"></iframe>
+                    <iframe src="<?php echo htmlspecialchars($video['url']); ?>?warningTitle='0'" 
+                            frameborder="0" 
+                            allowfullscreen="allowfullscreen" 
+                            allow="autoplay; fullscreen" 
+                            title="Lecteur vidéo: <?php echo htmlspecialchars($video['title']); ?>"
+                            aria-describedby="video-description">
+                    </iframe>
                 </div>
-            </div>
+            </section>
             
             <div class="video-content">
-                <div class="video-primary-info">
-                    <h1 class="video-title"><?php echo htmlspecialchars($video['title']); ?></h1>
+                <header class="video-primary-info">
+                    <h1 id="video-description" class="video-title" itemprop="name"><?php echo htmlspecialchars($video['title']); ?></h1>
                     
                     <div class="video-info">
                         <div class="video-metadata">
-                            <span class="video-views"><i class="fas fa-eye"></i> <?php echo formatViewCount($video['views']); ?> vues</span>
-                            <span class="video-date"><i class="far fa-calendar-alt"></i> <?php echo formatDate($video['date']); ?></span>
+                            <span class="video-views"><i class="fas fa-eye" aria-hidden="true"></i> <?php echo formatViewCount($video['views']); ?> vues</span>
+                            <span class="video-date"><i class="far fa-calendar-alt" aria-hidden="true"></i> <time datetime="<?php echo $video['date']; ?>"><?php echo formatDate($video['date']); ?></time></span>
                         </div>
                         
                         <div class="video-actions">
-                            <button class="action-button" id="share-btn">
-                                <i class="fas fa-share"></i>
+                            <button class="action-button" id="share-btn" aria-label="Partager cette vidéo">
+                                <i class="fas fa-share" aria-hidden="true"></i>
                                 <span>Partager</span>
                             </button>
-                            <button class="action-button" id="download-btn">
-                                <i class="fas fa-download"></i>
+                            <button class="action-button" id="download-btn" aria-label="Télécharger cette vidéo">
+                                <i class="fas fa-download" aria-hidden="true"></i>
                                 <span>Télécharger</span>
                             </button>
                         </div>
                     </div>
                     
                     <?php if (!empty($video['licence'])): ?>
-                    <div class="video-licence">
-                        <h4 class="licence-title">Licence</h4>
+                    <section class="video-licence">
+                        <h2 class="licence-title">Licence</h2>
                         <?php 
                         $licenceLabels = [
                             1 => "CC BY (Attribution)", 
@@ -257,36 +263,36 @@ if (empty($videoData) || isset($videoData['error'])) {
                             <span class="licence-label"><?php echo $licenceLabel; ?></span>
                             <?php endif; ?>
                         </div>
-                    </div>
+                    </section>
                     <?php endif; ?>
-                </div>
+                </header>
                 
-                <div class="video-secondary-info">
+                <section class="video-secondary-info">
                     <div class="channel-info">
                         <?php 
                         $channelUrl = PEERTUBE_URL . '/c/' . $video['channelHandle'];
                         ?>
                         <?php if (strpos($channelAvatar, 'default-avatar') !== false || empty($channelAvatar)): ?>
-                            <a href="<?php echo $channelUrl; ?>" target="_blank" rel="noopener noreferrer" class="channel-avatar-link">
-                                <div class="channel-avatar-placeholder">
-                                    <i class="fas fa-user-circle"></i>
+                            <a href="<?php echo $channelUrl; ?>" target="_blank" rel="noopener noreferrer" class="channel-avatar-link" aria-label="Voir la chaîne <?php echo htmlspecialchars($video['channel']); ?>">
+                                <div class="channel-avatar-placeholder" role="img" aria-label="Avatar par défaut">
+                                    <i class="fas fa-user-circle" aria-hidden="true"></i>
                                 </div>
                             </a>
                         <?php else: ?>
-                            <a href="<?php echo $channelUrl; ?>" target="_blank" rel="noopener noreferrer" class="channel-avatar-link">
+                            <a href="<?php echo $channelUrl; ?>" target="_blank" rel="noopener noreferrer" class="channel-avatar-link" aria-label="Voir la chaîne <?php echo htmlspecialchars($video['channel']); ?>">
                                 <div class="channel-avatar">
-                                    <img src="<?php echo $channelAvatar; ?>" alt="<?php echo $video['channel']; ?>">
+                                    <img src="<?php echo $channelAvatar; ?>" alt="Avatar de la chaîne <?php echo htmlspecialchars($video['channel']); ?>">
                                 </div>
                             </a>
                         <?php endif; ?>
                         <div class="channel-details">
                             <a href="<?php echo $channelUrl; ?>" target="_blank" rel="noopener noreferrer" class="channel-name-link">
-                                <h3 class="channel-name"><?php echo $video['channel']; ?></h3>
+                                <h2 class="channel-name"><?php echo htmlspecialchars($video['channel']); ?></h2>
                             </a>
                         </div>
                     </div>
                     
-                    <div class="video-description">
+                    <div class="video-description" itemprop="description">
                         <?php 
                         // Vérifier si on a une description tronquée et si la description complète est plus longue
                         $hasTruncatedDesc = !empty($video['truncatedDescription']) && 
@@ -296,16 +302,16 @@ if (empty($videoData) || isset($videoData['error'])) {
                         ?>
                             <div class="truncated-description">
                                 <?php echo markdown_to_html($video['truncatedDescription']); ?>
-                                <button class="show-more-btn">
+                                <button class="show-more-btn" aria-expanded="false" aria-controls="full-description">
                                     <span>Voir plus</span>
-                                    <i class="fas fa-chevron-down"></i>
+                                    <i class="fas fa-chevron-down" aria-hidden="true"></i>
                                 </button>
                             </div>
-                            <div class="full-description" style="display: none;">
+                            <div id="full-description" class="full-description" style="display: none;">
                                 <?php echo markdown_to_html($video['description']); ?>
-                                <button class="show-less-btn">
+                                <button class="show-less-btn" aria-expanded="true" aria-controls="full-description">
                                     <span>Voir moins</span>
-                                    <i class="fas fa-chevron-up"></i>
+                                    <i class="fas fa-chevron-up" aria-hidden="true"></i>
                                 </button>
                             </div>
                         <?php else: ?>
@@ -320,50 +326,50 @@ if (empty($videoData) || isset($videoData['error'])) {
                         <?php endforeach; ?>
                     </div>
                     <?php endif; ?>
-                </div>
+                </section>
                 
                 <!-- Commentaires -->
-                <div class="comments-section">
-                    <div class="section-header">
+                <section class="comments-section" aria-labelledby="comments-heading">
+                    <header class="section-header">
                         <div class="section-title-wrapper">
-                            <h2 class="section-title">Commentaires</h2>
+                            <h2 id="comments-heading" class="section-title">Commentaires</h2>
                         </div>
-                        <a href="<?php echo PEERTUBE_URL; ?>/videos/watch/<?php echo $videoData['uuid']; ?>" target="_blank" class="view-on-peertube">
-                            <i class="fas fa-external-link-alt"></i> Voir sur <?php echo PEERTUBE_DISPLAY_NAME; ?>
+                        <a href="<?php echo PEERTUBE_URL; ?>/videos/watch/<?php echo $videoData['uuid']; ?>" target="_blank" class="view-on-peertube" aria-label="Voir cette vidéo sur <?php echo PEERTUBE_DISPLAY_NAME; ?>">
+                            <i class="fas fa-external-link-alt" aria-hidden="true"></i> Voir sur <?php echo PEERTUBE_DISPLAY_NAME; ?>
                         </a>
-                    </div>
+                    </header>
                     <div class="comments-list">
                         <?php
                         $comments = getVideoComments($videoData['uuid']);
                         if (!empty($comments)):
                             foreach ($comments as $comment):
                         ?>
-                        <div class="comment">
+                        <article class="comment">
                             <div class="comment-avatar">
                                 <?php if (isset($comment['account']['avatar']) && !empty($comment['account']['avatar']['path'])): ?>
                                     <img src="<?php echo PEERTUBE_URL . $comment['account']['avatar']['path']; ?>" alt="<?php echo htmlspecialchars($comment['account']['displayName']); ?>">
                                 <?php else: ?>
-                                    <div class="channel-avatar-placeholder mini">
-                                        <i class="fas fa-user-circle"></i>
+                                    <div class="channel-avatar-placeholder mini" role="img" aria-label="Avatar par défaut">
+                                        <i class="fas fa-user-circle" aria-hidden="true"></i>
                                     </div>
                                 <?php endif; ?>
                             </div>
                             <div class="comment-content">
-                                <div class="comment-header">
+                                <header class="comment-header">
                                     <span class="comment-author"><?php echo htmlspecialchars($comment['account']['displayName']); ?></span>
-                                    <span class="comment-date"><?php echo formatDate($comment['createdAt']); ?></span>
-                                </div>
+                                    <time class="comment-date" datetime="<?php echo $comment['createdAt']; ?>"><?php echo formatDate($comment['createdAt']); ?></time>
+                                </header>
                                 <div class="comment-text"><?php echo nl2br(htmlspecialchars($comment['text'])); ?></div>
                                 
                                 <?php if (isset($comment['totalReplies']) && $comment['totalReplies'] > 0): ?>
                                 <div class="comment-replies-toggle">
-                                    <a href="<?php echo PEERTUBE_URL; ?>/videos/watch/<?php echo $videoData['uuid']; ?>" target="_blank" class="show-replies">
-                                        <i class="fas fa-reply"></i> Voir les <?php echo $comment['totalReplies']; ?> réponse<?php echo $comment['totalReplies'] > 1 ? 's' : ''; ?>
+                                    <a href="<?php echo PEERTUBE_URL; ?>/videos/watch/<?php echo $videoData['uuid']; ?>" target="_blank" class="show-replies" aria-label="Voir les réponses sur PeerTube">
+                                        <i class="fas fa-reply" aria-hidden="true"></i> Voir les <?php echo $comment['totalReplies']; ?> réponse<?php echo $comment['totalReplies'] > 1 ? 's' : ''; ?>
                                     </a>
                                 </div>
                                 <?php endif; ?>
                             </div>
-                        </div>
+                        </article>
                         <?php
                             endforeach;
                         ?>
@@ -383,19 +389,20 @@ if (empty($videoData) || isset($videoData['error'])) {
                 </div>
             </div>
             
-            <div class="video-suggestions">
-                <h3>Vidéos suggérées</h3>
+            <aside class="video-suggestions" aria-labelledby="suggestions-heading">
+                <h2 id="suggestions-heading">Vidéos suggérées</h2>
                 
                 <?php if (!empty($suggestedVideos)): ?>
                     <div class="suggestion-list">
                         <?php foreach ($suggestedVideos as $suggestedVideo): ?>
-                            <a href="video.php?id=<?php echo $suggestedVideo['id']; ?>" class="suggested-video">
+                            <article class="suggested-video">
+                                <a href="video.php?id=<?php echo $suggestedVideo['id']; ?>" class="suggested-video-link" aria-labelledby="suggestion-title-<?php echo $suggestedVideo['id']; ?>">
                                 <div class="suggested-video-thumbnail">
                                     <img src="<?php echo $suggestedVideo['thumbnail']; ?>" alt="<?php echo $suggestedVideo['title']; ?>">
                                 </div>
                                 <div class="suggested-video-info">
                                     <span class="suggested-video-duration"><?php echo formatDuration($suggestedVideo['duration']); ?></span>
-                                    <h4 class="suggested-video-title"><?php echo $suggestedVideo['title']; ?></h4>
+                                    <h3 id="suggestion-title-<?php echo $suggestedVideo['id']; ?>" class="suggested-video-title"><?php echo htmlspecialchars($suggestedVideo['title']); ?></h3>
                                     <div class="suggested-video-channel">
                                         <?php 
                                         // Vérifier si un avatar de chaîne est disponible pour la vidéo suggérée
@@ -416,16 +423,17 @@ if (empty($videoData) || isset($videoData['error'])) {
                                         <span class="suggested-video-date"><?php echo formatDate($suggestedVideo['date']); ?></span>
                                     </div>
                                 </div>
-                            </a>
+                                </a>
+                            </article>
                         <?php endforeach; ?>
                     </div>
                 <?php else: ?>
                     <p>Aucune vidéo suggérée disponible</p>
                 <?php endif; ?>
-            </div>
-        </div>
+            </aside>
+        </article>
         <?php endif; ?>
-    </div>
+    </main>
     <?php include 'includes/footer.php'; ?>
     <?php include 'includes/mobile-menu.php'; ?>