.menu-container {
            width: 260px;
            background: white;
            border-radius: 8px;
            box-shadow: 0 5px 15px rgba(0,0,0,0.1);
            overflow: hidden;
        }

        .menu-item {
            position: relative;
            border-bottom: 1px solid #eee;
        }

        .menu-item:last-child {
            border-bottom: none;
        }

        .menu-link {
            display: block;
            padding: 14px 20px;
            color: #333;
            text-decoration: none;
            transition: all 0.3s;
        }

        /* 一级菜单按钮效果 */
        .level-1 > .menu-link {
            background: #c62828;
            color: white;
            font-weight: bold;
            border-left: 4px solid #8e0000;
            text-align: left;
        }

        .level-1 > .menu-link:hover {
            background: #8e0000;
        }

        /* 二级菜单样式 */
        .level-2 > .menu-link {
            padding-left: 30px;
            text-align: left;
            background: #f9f9f9;
        }
        .level-2 > .menu-link:hover {
            background: #cccccc;
        }
        /* 三级菜单样式 */
        .level-3 > .menu-link {
            padding-left: 50px;
            background: #f0f0f0;
            font-size: 14px;
            text-align: left;
        }
        .level-3 > .menu-link:hover {
            background: #cccccc;
        }
        .has-children > .menu-link {
            position: relative;
        }

        .has-children > .menu-link::after {
            content: "+";
            position: absolute;
            right: 20px;
            font-size: 18px;
            transition: transform 0.3s;
        }

        .submenu {
            max-height: 0;
            overflow: hidden;
            transition: max-height 0.5s ease;
        }

        input[type="checkbox"] {
            display: none;
        }

        input[type="checkbox"]:checked ~ .submenu {
            max-height: 1000px;
        }

        input[type="checkbox"]:checked + .menu-link::after {
            transform: rotate(45deg);
        }

        .menu-link:active {
            transform: scale(0.98);
        }