some little fixes

web/css/index.css

@@ -631,6 +631,37 @@ body {
     box-shadow: none;
 }
 
+.add-button {
+    padding: 12px 20px;
+    background: linear-gradient(
+        135deg,
+        var(--primary-color),
+        var(--primary-hover)
+    );
+    color: white;
+    border: none;
+    border-radius: 25px;
+    cursor: pointer;
+    font-size: 14px;
+    font-weight: 600;
+    transition: all 0.3s ease;
+    flex-shrink: 0;
+    min-height: 44px;
+}
+
+.add-button:hover:not(:disabled) {
+    transform: translateY(-2px);
+    box-shadow: 0 5px 15px rgba(52, 152, 219, 0.4);
+}
+
+.add-button:disabled {
+    background: var(--bg-tertiary);
+    color: var(--text-secondary);
+    cursor: not-allowed;
+    transform: none;
+    box-shadow: none;
+}
+
 .system-message {
     text-align: center;
     color: var(--text-secondary);