add calendar icon next to the tasks to edit dates within the gant

public/css/style.css

@@ -1249,6 +1249,39 @@ GANTT
     font-size: 11px; 
     color: var(--fg-muted); 
     padding-left: 20px;
+    display: flex;
+    align-items: center;
+    justify-content: space-between;
+    gap: 6px;
+}
+
+.gantt-ticket-id-label {
+    overflow: hidden;
+    text-overflow: ellipsis;
+    white-space: nowrap;
+}
+
+.gantt-date-edit-btn {
+    flex-shrink: 0;
+    display: inline-flex;
+    align-items: center;
+    justify-content: center;
+    width: 22px;
+    height: 22px;
+    border-radius: 6px;
+    border: 1px solid var(--border);
+    background: var(--bg-input);
+    color: var(--accent);
+    font-size: 11px;
+    cursor: pointer;
+    margin-right: 8px;
+    transition: all 0.2s ease;
+}
+
+.gantt-date-edit-btn:hover {
+    background: var(--accent-glow);
+    border-color: var(--accent);
+    transform: scale(1.08);
 }
 
 /* Grille de fond (colonnes verticales sous les barres) */
@@ -1353,4 +1386,99 @@ GANTT
 
 .mr-4 { margin-right: 4px; }
 
+/* --- Date Edit Modal --- */
+.modal-overlay {
+    display: none;
+    position: fixed;
+    inset: 0;
+    z-index: 9998;
+    background: rgba(0, 0, 0, 0.55);
+    align-items: center;
+    justify-content: center;
+    animation: fadeIn 0.2s ease;
+}
+
+.modal-overlay.visible {
+    display: flex;
+}
+
+.modal-box {
+    background: var(--bg-card);
+    border: 1px solid var(--border);
+    border-radius: var(--radius-lg);
+    box-shadow: var(--shadow);
+    width: 100%;
+    max-width: 420px;
+    margin: 20px;
+    overflow: hidden;
+}
+
+.modal-header {
+    display: flex;
+    align-items: center;
+    justify-content: space-between;
+    padding: 18px 20px;
+    border-bottom: 1px solid var(--border);
+}
+
+.modal-title {
+    display: flex;
+    align-items: center;
+    gap: 10px;
+    font-size: 15px;
+    font-weight: 700;
+    color: var(--fg);
+}
+
+.modal-title i { color: var(--accent); }
+
+.modal-close {
+    background: transparent;
+    border: none;
+    color: var(--fg-muted);
+    font-size: 16px;
+    cursor: pointer;
+    padding: 4px;
+    line-height: 1;
+    border-radius: 6px;
+    transition: all 0.2s ease;
+}
+
+.modal-close:hover {
+    color: var(--danger);
+    background: var(--accent-glow);
+}
+
+.modal-body {
+    padding: 20px;
+    display: flex;
+    flex-direction: column;
+    gap: 16px;
+}
+
+.modal-ticket-key {
+    font-family: 'JetBrains Mono', monospace;
+    font-weight: 700;
+    color: var(--accent);
+    font-size: 13px;
+}
+
+.modal-ticket-summary {
+    font-size: 12px;
+    color: var(--fg-muted);
+    margin-top: -10px;
+}
+
+.modal-date-input {
+    width: 100%;
+}
+
+.modal-footer {
+    display: flex;
+    justify-content: flex-end;
+    gap: 10px;
+    padding: 16px 20px;
+    border-top: 1px solid var(--border);
+}
+