/* 页脚 */
        footer {
            background-color: #2c3e50;
            color: #ecf0f1;
            padding: 60px 0 30px;
        }
        
        .footer-content {
            display: flex;
            justify-content: space-between;
            flex-wrap: wrap;
            margin-bottom: 40px;
        }
        
        .footer-column {
            flex-basis: 23%;
            margin-bottom: 30px;
        }
        
        .footer-column h3 {
            font-size: 18px;
            margin-bottom: 20px;
            color: #3498db;
            position: relative;
            padding-bottom: 10px;
        }
        
        .footer-column h3:after {
            content: '';
            position: absolute;
            width: 40px;
            height: 2px;
            background-color: #3498db;
            bottom: 0;
            left: 0;
        }
        
        .footer-column ul {
            list-style: none;
        }
        
        .footer-column li {
            margin-bottom: 10px;
        }
        
        .footer-column a {
            color: #bdc3c7;
            text-decoration: none;
            transition: color 0.3s;
        }
        
        .footer-column a:hover {
            color: #3498db;
        }
        
        .copyright p {
            text-align: center;
            padding-top: 20px;
            border-top: 1px solid #34495e;
            font-size: 14px;
            color: #95a5a6;
        }
        
        /* 响应式设计 */
        @media (max-width: 992px) {
            .service-card {
                flex-basis: calc(50% - 20px);
            }
            
            .advantages {
                grid-template-columns: 1fr;
            }
            
            .footer-column {
                flex-basis: 48%;
            }
        }
        
        @media (max-width: 768px) {
            .mobile-menu {
                display: block;
            }
            
            nav ul {
                display: none;
                position: absolute;
                top: 100%;
                left: 0;
                width: 100%;
                background-color: white;
                flex-direction: column;
                box-shadow: 0 5px 10px rgba(0, 0, 0, 0.1);
            }
            
            nav li {
                margin: 0;
                border-bottom: 1px solid #eee;
            }
            
            nav a {
                display: block;
                padding: 15px 20px;
            }

             /* 移动端下拉菜单保持垂直排列 */
            .dropdown-menu {
                position: static;
                opacity: 1;
                visibility: visible;
                transform: none;
                box-shadow: none;
                background: #f8f9fa;
                display: block;
                min-width: 100%;
            }
            
            .dropdown-menu li {
                border-bottom: 1px solid #e0e0e0;
            }
            
            .dropdown-menu a {
                padding-left: 40px;
                text-align: left;
            }
            
            .service-card {
                flex-basis: 100%;
            }
            
            .footer-column {
                flex-basis: 100%;
            }
            
            .banner h2 {
                font-size: 28px;
            }
            
            .banner p {
                font-size: 16px;
            }
        }