diff --git a/index.html b/index.html
index 5eb7017..678f600 100644
--- a/index.html
+++ b/index.html
@@ -7,6 +7,12 @@
     <link href="https://fonts.googleapis.com/css2?family=JetBrains+Mono:wght@400;600&family=DM+Sans:wght@300;400;500;600;700;900&display=swap" rel="stylesheet">
     <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.5.0/css/all.min.css">
     <link rel="stylesheet" href="css/style.css">
+    <script>
+        (function() {
+            const savedTheme = localStorage.getItem('jira_extractor_theme') || 'dark';
+            document.documentElement.setAttribute('data-theme', savedTheme);
+        })();
+    </script>
 </head>
 <body>
     <div class="bg-grid"></div>
@@ -20,7 +26,13 @@
                 <h1>Jira Ticket Extractor</h1>
                 <p>Extraction via API locale — Proxy transparent</p>
             </div>
-            <div class="badge-api"><i class="fa-solid fa-server"></i>API : localhost:3000</div>
+            <div class="header-actions">
+                <div class="badge-api"><i class="fa-solid fa-server"></i>API : localhost:3000</div>
+                <button class="theme-toggle-btn" id="themeToggleBtn" onclick="toggleTheme()" aria-label="Changer de thème" title="Basculer vers le mode clair / sombre">
+                    <i class="fa-solid fa-sun" id="themeIcon"></i>
+                    <span id="themeLabel">Mode clair</span>
+                </button>
+            </div>
         </header>
 
         <section class="card-form">
diff --git a/public/css/style.css b/public/css/style.css
index 76dc0fe..3bcb64e 100644
--- a/public/css/style.css
+++ b/public/css/style.css
@@ -17,6 +17,37 @@
     --radius: 10px;
     --radius-lg: 16px;
     --shadow: 0 4px 24px rgba(0, 0, 0, 0.4);
+    --fg-btn-primary: #0f0a0f;
+    --gantt-bg: #0a0f0d;
+    --gantt-header-bg: #111a16;
+    --gantt-sticky-bg: #1a1a1a;
+    --gantt-group-bg: rgba(255, 255, 255, 0.03);
+    --gantt-grid-border: rgba(255, 255, 255, 0.05);
+}
+
+[data-theme="light"] {
+    --bg: #f3f6f4;
+    --bg-elevated: #ffffff;
+    --bg-card: #ffffff;
+    --bg-input: #f8faf9;
+    --fg: #13221b;
+    --fg-muted: #4e6b5d;
+    --fg-dim: #8ba295;
+    --accent: #00995c;
+    --accent-dim: #007a49;
+    --accent-glow: rgba(0, 153, 92, 0.12);
+    --accent-glow-strong: rgba(0, 153, 92, 0.22);
+    --border: #d2ded6;
+    --danger: #dc2626;
+    --warning: #d97706;
+    --info: #0284c7;
+    --shadow: 0 4px 20px rgba(0, 0, 0, 0.06);
+    --fg-btn-primary: #ffffff;
+    --gantt-bg: #f8faf9;
+    --gantt-header-bg: #eef4f0;
+    --gantt-sticky-bg: #e6ede8;
+    --gantt-group-bg: rgba(0, 0, 0, 0.03);
+    --gantt-grid-border: rgba(0, 0, 0, 0.06);
 }
 
 * {
@@ -30,6 +61,7 @@ body {
     background: var(--bg);
     color: var(--fg);
     min-height: 100vh;
+    transition: background-color 0.25s ease, color 0.25s ease;
 }
 
 .bg-grid {
@@ -88,6 +120,7 @@ body {
     margin-bottom: 40px;
     padding-bottom: 24px;
     border-bottom: 1px solid var(--border);
+    flex-wrap: wrap;
 }
 
 .header-icon {
@@ -99,7 +132,7 @@ body {
     align-items: center;
     justify-content: center;
     font-size: 22px;
-    color: var(--bg);
+    color: var(--fg-btn-primary);
     box-shadow: 0 0 30px var(--accent-glow-strong);
 }
 
@@ -115,16 +148,68 @@ body {
     margin-top: 4px;
 }
 
+.header-actions {
+    display: flex;
+    align-items: center;
+    gap: 12px;
+    margin-left: auto;
+}
+
 .badge-api {
     background: var(--accent-glow);
     color: var(--accent);
     font-size: 11px;
     font-weight: 700;
-    padding: 4px 10px;
+    padding: 6px 12px;
     border-radius: 20px;
     border: 1px solid rgba(0, 230, 138, 0.2);
-    margin-left: auto;
     font-family: 'JetBrains Mono', monospace;
+    display: inline-flex;
+    align-items: center;
+}
+
+[data-theme="light"] .badge-api {
+    border-color: rgba(0, 153, 92, 0.25);
+}
+
+.theme-toggle-btn {
+    display: inline-flex;
+    align-items: center;
+    gap: 8px;
+    background: var(--bg-card);
+    color: var(--fg);
+    border: 1px solid var(--border);
+    border-radius: 20px;
+    padding: 6px 14px;
+    font-family: 'DM Sans', sans-serif;
+    font-size: 12px;
+    font-weight: 600;
+    cursor: pointer;
+    transition: all 0.25s ease;
+    outline: none;
+    user-select: none;
+    box-shadow: var(--shadow);
+}
+
+.theme-toggle-btn:hover {
+    border-color: var(--accent);
+    background: var(--accent-glow);
+    color: var(--accent);
+    transform: translateY(-1px);
+}
+
+.theme-toggle-btn i {
+    font-size: 13px;
+    color: var(--warning);
+    transition: transform 0.3s ease;
+}
+
+[data-theme="light"] .theme-toggle-btn i {
+    color: var(--info);
+}
+
+.theme-toggle-btn:hover i {
+    transform: rotate(25deg);
 }
 
 .card-form {
@@ -230,7 +315,7 @@ body {
 
 .btn-primary {
     background: linear-gradient(135deg, var(--accent), var(--accent-dim));
-    color: var(--bg);
+    color: var(--fg-btn-primary);
     box-shadow: 0 4px 20px var(--accent-glow-strong);
 }
 
@@ -252,6 +337,7 @@ body {
 
 .btn-secondary:hover {
     border-color: var(--fg-dim);
+    background: var(--bg-elevated);
 }
 
 .btn-danger {
@@ -260,6 +346,11 @@ body {
     border: 1px solid rgba(255, 77, 106, 0.2);
 }
 
+[data-theme="light"] .btn-danger {
+    background: rgba(220, 38, 38, 0.08);
+    border-color: rgba(220, 38, 38, 0.2);
+}
+
 .btn-group {
     display: flex;
     gap: 12px;
@@ -380,7 +471,7 @@ body {
 
 .tab-btn.active {
     background: var(--accent);
-    color: var(--bg);
+    color: var(--fg-btn-primary);
     box-shadow: 0 2px 12px var(--accent-glow-strong);
 }
 
@@ -435,7 +526,7 @@ td {
 }
 
 tr:hover td {
-    background: rgba(0, 230, 138, 0.03);
+    background: var(--accent-glow);
 }
 
 .ticket-key {
@@ -481,6 +572,31 @@ tr:hover td {
     color: #7a9488;
 }
 
+[data-theme="light"] .s-done {
+    background: rgba(0, 153, 92, 0.12);
+    color: #007a49;
+}
+
+[data-theme="light"] .s-progress {
+    background: rgba(2, 132, 199, 0.12);
+    color: #0284c7;
+}
+
+[data-theme="light"] .s-todo {
+    background: rgba(217, 119, 6, 0.12);
+    color: #b45309;
+}
+
+[data-theme="light"] .s-blocked {
+    background: rgba(220, 38, 38, 0.12);
+    color: #dc2626;
+}
+
+[data-theme="light"] .s-other {
+    background: rgba(83, 110, 97, 0.12);
+    color: #4e6b5d;
+}
+
 .empty-cell {
     color: var(--fg-dim);
     font-style: italic;
@@ -515,6 +631,10 @@ tr:hover td {
     opacity: 1;
 }
 
+[data-theme="light"] .date-input::-webkit-calendar-picker-indicator {
+    filter: none;
+}
+
 /* Update button styling */
 .btn-update {
     display: inline-flex;
@@ -529,7 +649,7 @@ tr:hover td {
     cursor: pointer;
     transition: all 0.25s;
     background: linear-gradient(135deg, var(--accent), var(--accent-dim));
-    color: var(--bg);
+    color: var(--fg-btn-primary);
 }
 
 .btn-update:hover {
@@ -588,6 +708,22 @@ tr:hover td {
     color: var(--fg-dim);
 }
 
+[data-theme="light"] .json-key {
+    color: #0284c7;
+}
+
+[data-theme="light"] .json-string {
+    color: #00874e;
+}
+
+[data-theme="light"] .json-number {
+    color: #d97706;
+}
+
+[data-theme="light"] .json-bool {
+    color: #dc2626;
+}
+
 .search-bar {
     position: relative;
     margin-bottom: 16px;
@@ -646,7 +782,7 @@ tr:hover td {
     display: flex;
     align-items: center;
     gap: 10px;
-    box-shadow: 0 8px 30px rgba(0, 0, 0, 0.5);
+    box-shadow: var(--shadow);
     animation: tIn 0.35s ease, tOut 0.35s ease 3s forwards;
     max-width: 400px;
 }
@@ -663,6 +799,18 @@ tr:hover td {
     color: var(--danger);
 }
 
+[data-theme="light"] .toast-success {
+    background: #ecfdf5;
+    border: 1px solid rgba(0, 153, 92, 0.3);
+    color: #065f46;
+}
+
+[data-theme="light"] .toast-error {
+    background: #fef2f2;
+    border: 1px solid rgba(220, 38, 38, 0.3);
+    color: #991b1b;
+}
+
 @keyframes tIn {
     from {
         opacity: 0;
@@ -781,8 +929,8 @@ GANTT
     position: relative;
     height: 600px; 
     overflow: auto; /* Un seul scroll géré ici */
-    background: #0a0f0d;
-    border: 1px solid #1e3028;
+    background: var(--gantt-bg);
+    border: 1px solid var(--border);
     border-radius: 8px;
 }
 
@@ -792,27 +940,27 @@ GANTT
     position: sticky;
     top: 0;
     z-index: 100;
-    background: #111a16;
-    border-bottom: 2px solid #1e3028;
+    background: var(--gantt-header-bg);
+    border-bottom: 2px solid var(--border);
 }
 
 .gantt-header-label {
     position: sticky;
     left: 0;
     z-index: 101;
-    background: #1a1a1a;
+    background: var(--gantt-sticky-bg);
     border-right: 2px solid var(--border);
     padding-left: 10px;
     display: flex;
     align-items: center;
     font-weight: bold;
-    color: var(--primary);
+    color: var(--accent);
 }
 
 /* Groupes par Assigné */
 .gantt-group-row {
     display: flex;
-    background: rgba(255, 255, 255, 0.03);
+    background: var(--gantt-group-bg);
     border-bottom: 1px solid var(--border);
     font-weight: 600;
 }
@@ -821,7 +969,7 @@ GANTT
     position: sticky;
     left: 0;
     z-index: 50;
-    background: #1a1a1a;
+    background: var(--gantt-sticky-bg);
     padding: 8px 10px;
     border-right: 2px solid var(--border);
     color: var(--accent);
@@ -860,7 +1008,7 @@ GANTT
     align-items: center;
     padding: 0 8px;
     font-size: 10px;
-    color: white;
+    color: var(--fg);
     overflow: hidden;
     white-space: nowrap;
     text-overflow: ellipsis;
@@ -873,8 +1021,8 @@ GANTT
     position: sticky;
     left: 0;
     z-index: 110;
-    background: #111a16;
-    border-right: 2px solid #1e3028;
+    background: var(--gantt-header-bg);
+    border-right: 2px solid var(--border);
     padding: 0 10px;
     display: flex;
     align-items: center;
@@ -886,7 +1034,7 @@ GANTT
     top: 0;
     bottom: 0;
     width: 2px;
-    background-color: #ff4d6a;
+    background-color: var(--danger);
     z-index: 80;
     pointer-events: none;
 }
@@ -895,7 +1043,7 @@ GANTT
     position: absolute;
     top: 2px;
     transform: translateX(-50%);
-    background: #ff4d6a;
+    background: var(--danger);
     color: white;
     padding: 2px 5px;
     border-radius: 3px;
@@ -919,18 +1067,18 @@ GANTT
     width: 140px;
     text-align: center;
     font-size: 11px;
-    color: #7a9488;
+    color: var(--fg-muted);
     display: flex;
     align-items: center;
     justify-content: center;
-    border-left: 1px solid #1e3028;
+    border-left: 1px solid var(--border);
 }
 
 /* Ligne de groupe (Assigné) */
 .gantt-group-header {
     display: flex; 
-    background: rgba(255, 255, 255, 0.03); 
-    border-bottom: 1px solid #1e3028;
+    background: var(--gantt-group-bg); 
+    border-bottom: 1px solid var(--border);
 }
 
 .gantt-group-name {
@@ -944,7 +1092,7 @@ GANTT
 .gantt-row {
     display: flex; 
     height: 45px; 
-    border-bottom: 1px solid #1e3028; 
+    border-bottom: 1px solid var(--border); 
     position: relative; 
     align-items: center;
 }
@@ -953,14 +1101,14 @@ GANTT
     width: 250px; /* leftWidth */
     height: 100%; 
     font-size: 11px; 
-    color: #7a9488; 
+    color: var(--fg-muted); 
     padding-left: 20px;
 }
 
 /* Grille de fond (colonnes verticales sous les barres) */
 .gantt-grid-col {
     min-width: 140px;
-    border-right: 1px solid rgba(255, 255, 255, 0.05);
+    border-right: 1px solid var(--gantt-grid-border);
     height: 100%;
 }
 
@@ -974,9 +1122,9 @@ GANTT
 
 /* Optionnel : style pour le bouton de vue actif */
 .view-controls .btn.active {
-    background-color: var(--primary);
-    color: white;
-    border-color: var(--primary);
+    background-color: var(--accent);
+    color: var(--fg-btn-primary);
+    border-color: var(--accent);
 }
 /* --- ALIGNEMENT ROADMAP --- */
 
@@ -1003,7 +1151,7 @@ GANTT
     margin-left: auto; /* Sécurité supplémentaire pour pousser à droite */
     border: 1px solid var(--accent); /* Optionnel: pour bien la voir */
     border-radius: var(--radius-lg);
-    background: rgba(0, 230, 138, 0.05);
+    background: var(--accent-glow);
     padding: 5px 15px;
 }
 
@@ -1012,8 +1160,8 @@ GANTT
     display: flex;
     align-items: center;
     gap: 15px;
-    background: rgba(0, 230, 138, 0.1); /* Fond vert transparent */
-    border: 1px solid var(--accent);   /* Bordure verte */
+    background: var(--accent-glow);
+    border: 1px solid var(--accent);
     padding: 6px 15px;
     border-radius: var(--radius);
 }
diff --git a/public/js/script.js b/public/js/script.js
index 1404093..82d3ae3 100644
--- a/public/js/script.js
+++ b/public/js/script.js
@@ -9,6 +9,39 @@ let currentSortCol = null;
 let isAsc = true;
 
 
+// --- GESTION DU THÈME (CLAIR / SOMBRE) ---
+function initTheme() {
+    const savedTheme = localStorage.getItem('jira_extractor_theme') || 'dark';
+    setTheme(savedTheme, false);
+}
+
+function toggleTheme() {
+    const currentTheme = document.documentElement.getAttribute('data-theme') === 'light' ? 'light' : 'dark';
+    const newTheme = currentTheme === 'light' ? 'dark' : 'light';
+    setTheme(newTheme, true);
+}
+
+function setTheme(theme, withToast = false) {
+    document.documentElement.setAttribute('data-theme', theme);
+    localStorage.setItem('jira_extractor_theme', theme);
+
+    const icon = document.getElementById('themeIcon');
+    const label = document.getElementById('themeLabel');
+    if (icon && label) {
+        if (theme === 'light') {
+            icon.className = 'fa-solid fa-moon';
+            label.textContent = 'Mode sombre';
+        } else {
+            icon.className = 'fa-solid fa-sun';
+            label.textContent = 'Mode clair';
+        }
+    }
+
+    if (withToast) {
+        showToast(theme === 'light' ? 'Mode clair activé' : 'Mode sombre activé');
+    }
+}
+
 // Sauvegarde les paramètres dans le stockage local du navigateur
 function saveSettings() {
     const settings = {
@@ -682,6 +715,7 @@ function clearResults() { allTickets=[]; filteredTickets=[]; document.getElement
 document.addEventListener('keydown', e => { if((e.ctrlKey||e.metaKey)&&e.key==='Enter'){e.preventDefault();startExtraction()} });
 // Cet événement se déclenche quand le navigateur a fini de charger le HTML
 document.addEventListener('DOMContentLoaded', () => {
+    initTheme();
     loadSettings();
     console.log("Paramètres chargés depuis le stockage local.");
 });
\ No newline at end of file