/* 导航栏 - 响应式设计 */
        header {
            background: var(--primary);
            position: fixed;
            width: 100%;
            top: 0;
            z-index: 1000;
            transition: all 0.3s ease;
            box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
        }
        
        .nav-container {
            display: flex;
            justify-content: space-between;
            align-items: center;
            padding: 15px 0;
            position: relative;
        }
        
        .logo {
            color: var(--white);
            font-size: 1.8rem;
            font-weight: 700;
            text-decoration: none;
            display: flex;
            align-items: center;
        }
        
        .logo span {
            color: var(--white);
            margin-left: 5px;
        }
        
        /* 桌面端导航 */
        .desktop-nav {
            display: flex;
            align-items: center;
            gap: 30px;
        }
        
        .nav-link {
            color: var(--white);
            text-decoration: none;
            font-weight: 500;
            transition: color 0.3s;
            position: relative;
            padding: 10px 0;
            font-size: 1.05rem;
        }
        
        .nav-link:hover {
            color: var(--secondary);
        }
        
        /* 二级菜单样式 */
        .nav-item {
            position: relative;
        }
        
        .dropdown-menu {
            position: absolute;
            top: 100%;
            left: 0;
            background: var(--white);
            min-width: 200px;
            box-shadow: 0 10px 30px rgba(0, 0, 0, 0.15);
            border-radius: 8px;
            opacity: 0;
            visibility: hidden;
            transform: translateY(10px);
            transition: all 0.3s ease;
            z-index: 1000;
            padding: 20px;
            display: flex;
            gap: 20px;
        }
        
        .dropdown-menu::before {
            content: '';
            position: absolute;
            top: -10px;
            left: 20px;
            border-width: 0 10px 10px 10px;
            border-style: solid;
            border-color: transparent transparent var(--white) transparent;
        }
        
        .nav-item:hover .dropdown-menu {
            opacity: 1;
            visibility: visible;
            transform: translateY(0);
        }
        
        .dropdown-column {
            flex: 1;
        }
        
        .dropdown-title {
            font-size: 1.1rem;
            font-weight: 600;
            color: var(--primary);
            margin-bottom: 15px;
            padding-bottom: 8px;
            border-bottom: 1px solid var(--gray-light);
        }
        
        .dropdown-item {
            display: flex;
            align-items: center;
            padding: 10px 0;
            color: var(--text-dark);
            text-decoration: none;
            transition: all 0.2s ease;
            font-size: 0.95rem;
        }
        
        .dropdown-item:hover {
            color: var(--primary);
        }
        
        .dropdown-item i {
            margin-right: 8px;
            color: var(--secondary);
            font-size: 0.9rem;
        }
        
        .dropdown-item.star i {
            color: var(--secondary);
        }
        
        .nav-link i {
            margin-left: 5px;
            transition: transform 0.3s;
            font-size: 0.8rem;
        }
        
        .nav-item:hover .nav-link i {
            transform: rotate(180deg);
        }
        
        /* 移动端菜单按钮 */
        .mobile-menu-btn {
            display: none;
            background: none;
            border: none;
            color: var(--white);
            font-size: 1.5rem;
            cursor: pointer;
            padding: 5px;
        }
        
        /* 移动端导航菜单 */
        .mobile-nav {
            display: none;
            position: absolute;
            top: 100%;
            left: 0;
            width: 100%;
            background: var(--primary-dark);
            z-index: 1000;
            box-shadow: 0 10px 20px rgba(0, 0, 0, 0.1);
            max-height: 0;
            overflow: hidden;
            transition: max-height 0.3s ease;
        }
        
        .mobile-nav.active {
            display: block;
            max-height: 500px;
        }
        
        .mobile-nav-list {
            list-style: none;
            padding: 20px;
        }
        
        .mobile-nav-item {
            margin-bottom: 10px;
        }
        
        .mobile-nav-link {
            color: var(--white);
            text-decoration: none;
            font-size: 1.1rem;
            padding: 12px 15px;
            border-radius: 5px;
            transition: all 0.3s;
            display: flex;
            justify-content: space-between;
            align-items: center;
        }
        
        .mobile-nav-link:hover {
            background: rgba(255, 255, 255, 0.1);
            color: var(--secondary);
        }
        
        .mobile-dropdown {
            overflow: hidden;
            max-height: 0;
            transition: max-height 0.3s ease;
        }
        
        .mobile-dropdown.active {
            max-height: 300px;
        }
        
        .mobile-dropdown-menu {
            padding-left: 25px;
            list-style: none;
            margin-top: 5px;
        }
        
        .mobile-dropdown-item {
            color: #d1d5db;
            text-decoration: none;
            padding: 10px 15px;
            border-radius: 5px;
            transition: all 0.3s;
            display: flex;
            align-items: center;
            gap: 10px;
            font-size: 0.95rem;
        }
        
        .mobile-dropdown-item:hover {
            background: rgba(255, 255, 255, 0.1);
            color: var(--secondary);
        }
        
        .mobile-dropdown-item i {
            font-size: 0.9rem;
        }







         /* 页脚 */
        footer {
            background: var(--dark);
            color: var(--white);
            padding: 60px 0 30px;
        }
        
        .footer-content {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
            gap: 40px;
            margin-bottom: 40px;
        }
        
        .footer-column h3 {
            font-size: 1.3rem;
            margin-bottom: 20px;
            color: var(--secondary);
            position: relative;
            padding-bottom: 10px;
        }
        
        .footer-column h3::after {
            content: '';
            position: absolute;
            bottom: 0;
            left: 0;
            width: 40px;
            height: 2px;
            background: var(--secondary);
        }
        
        .footer-links {
            list-style: none;
        }
        
        .footer-links li {
            margin-bottom: 12px;
        }
        
        .footer-links a {
            color: #d1d5db;
            text-decoration: none;
            transition: all 0.3s;
            display: flex;
            align-items: center;
        }
        
        .footer-links a:hover {
            color: var(--secondary);
            transform: translateX(5px);
        }
        
        .footer-links a i {
            margin-right: 8px;
            color: var(--secondary);
            font-size: 0.9rem;
        }
        
        .contact-info {
            list-style: none;
        }
        
        .contact-info li {
            display: flex;
            align-items: center;
            gap: 10px;
            margin-bottom: 15px;
            color: #d1d5db;
        }
        
        .contact-info i {
            color: var(--secondary);
            width: 20px;
        }
        
        .footer-bottom {
            text-align: center;
            padding-top: 30px;
            border-top: 1px solid #374151;
            color: #9ca3af;
            font-size: 0.9rem;
        }
        .footer-bottom a{text-decoration: none;color: #9ca3af}



        /* 导航栏滚动效果 */
        header.scrolled {
            box-shadow: 0 5px 20px rgba(0, 0, 0, 0.15);
            padding: 5px 0;
            background: rgba(26, 93, 169, 0.95);
            backdrop-filter: blur(10px);
        }