style: 优化级联选择器暗黑模式样式

frontend/src/views/CreateTask.vue

@@ -67,6 +67,7 @@
                         expand-trigger="hover"
                         :show-search="{ filter: cascaderFilter }"
                         @change="(value: any) => onTaskTypeChange(value, item, index)"
+                        popup-class-name="task-type-cascader-popup"
                       >
                         <template #displayRender="{ labels }">
                           <span>{{ labels.join(' / ') }}</span>
@@ -2182,3 +2183,61 @@ onUnmounted(() => {
 }
 </style>
 
+
+<style lang="scss">
+@import '@/styles/variables.scss';
+
+// 自定义级联选择器下拉弹窗样式（挂载在body下，需全局覆盖）
+.task-type-cascader-popup {
+  background-color: #1f1f1f !important; // 强制深色背景
+  border: 1px solid #303030 !important;
+  box-shadow: 0 6px 16px rgba(0, 0, 0, 0.6) !important;
+  border-radius: 8px !important;
+  padding: 4px !important;
+
+  .ant-cascader-menu {
+    background: transparent !important;
+    border-right: 1px solid #303030 !important;
+    height: 280px !important; // 增加高度以便容纳更多选项
+
+    &:last-child {
+      border-right: none !important;
+    }
+
+    .ant-cascader-menu-item {
+      color: #a0a0a0; // 普通文字颜色
+      padding: 10px 16px;
+      margin: 2px 4px;
+      border-radius: 6px;
+      transition: all 0.2s;
+      
+      &:hover {
+        background-color: rgba(255, 255, 255, 0.08) !important;
+        color: #e5e5e5;
+      }
+
+      // 激活/选中状态
+      &-active {
+        background-color: rgba(49, 240, 139, 0.15) !important; // 品牌色背景
+        color: #31f08b !important; // 品牌色文字
+        font-weight: 600;
+        
+        // 覆盖箭头颜色
+        .ant-cascader-menu-item-expand-icon {
+          color: #31f08b !important;
+        }
+      }
+      
+      // 展开图标
+      &-expand-icon {
+        color: #555;
+      }
+    }
+  }
+  
+  // 搜索结果高亮
+  .ant-cascader-menu-item-keyword {
+    color: #31f08b !important;
+  }
+}
+</style>