/* CSS变量定义 - 主题颜色 */
        :root {
            --primary: #0F3460;      /* 主色调：深蓝色 */
            --secondary: #D4AF37;    /* 辅色调：金黄色 */
            --dropdown-bg: #001991;  /* 下拉菜单背景色 */
        }

        /* 全局样式重置 */
        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
        }

        /* 页面基础样式 */
        body {
            background-color: #f5f5f5;
            color: #333;
            line-height: 1.6;
        }

        /* 容器样式 - 控制页面内容宽度 */
        .container {
            width: 100%;
            max-width: 1200px;
            margin: 0 auto;
            padding: 0 15px;
        }

        /* ==================== 顶部导航栏 ==================== */
        .top-nav {
            background-color: white;
            box-shadow: 0 2px 10px rgba(0,0,0,0.1);
            position: sticky;
            top: 0;
            z-index: 1000;
        }

        .nav-container {
            display: flex;
            justify-content: space-between;
            align-items: center;
            padding: 15px 0;
        }

        /* Logo样式 */
        .logo h1 {
            font-size: 28px;
            font-weight: 700;
            color: var(--primary);
        }

        .logo span {
            color: var(--secondary);
        }

        /* ==================== 主导航样式 ==================== */
        .main-nav ul {
            display: flex;
            align-items: center;
        }

        .main-nav ul li {
            margin-left: 40px;
            position: relative;
        }

        .main-nav ul li a {
            font-weight: 600;
            font-size: 16px;
            padding: 10px 0;
            display: flex;
            align-items: center;
            transition: color 0.3s;
        }

        .main-nav ul li a:hover {
            color: var(--secondary);
        }

        /* 激活状态的菜单项 */
        .active-menu-item a {
            color: var(--secondary);
            border-bottom: 2px solid var(--secondary);
        }

        /* ==================== 下拉菜单样式 ==================== */
        .dropdown {
            position: static;
        }

        /* 下拉菜单内容容器 */
        .dropdown-content {
            position: absolute;
            top: 100%;
            left: 0;
            width: 100%;
            background-color: var(--dropdown-bg);
            padding: 0;
            display: none;
            grid-template-columns: 280px 1fr;
            gap: 0;
            opacity: 0;
            transform: translateY(10px);
            transition: opacity 0.3s, transform 0.3s;
            z-index: 1000;
            box-shadow: 0 10px 30px rgba(0, 0, 0, 0.5);
        }

        /* 鼠标悬停时显示下拉菜单 */
        .dropdown:hover .dropdown-content {
            display: grid;
            opacity: 1;
            transform: translateY(0);
        }

        /* 下拉菜单左侧 - 图片区域 */
        .dropdown-left {
            background-color: var(--dropdown-bg);
            padding: 40px 30px;
            display: flex;
            flex-direction: column;
            justify-content: center;
            align-items: center;
            position: relative;
        }

        .menu-image {
            width: 100%;
            height: 220px;
            border-radius: 4px;
            overflow: hidden;
            margin-bottom: 25px;
            border: 1px solid rgba(255, 255, 255, 0.1);
        }

        .menu-image img {
            width: 100%;
            height: 100%;
            object-fit: cover;
        }

        /* 左侧图片区域的标题和描述 */
        .menu-title {
            color: white;
            font-size: 24px;
            font-weight: 700;
            margin-bottom: 15px;
            text-align: center;
            letter-spacing: 1px;
        }

        .menu-desc {
            color: rgba(255, 255, 255, 0.7);
            font-size: 14px;
            line-height: 1.5;
            text-align: center;
            max-width: 220px;
        }

        /* 下拉菜单右侧 - 子菜单区域 */
        .dropdown-right {
            padding: 40px 30px;
            background-color: var(--dropdown-bg);
            display: flex;
            flex-direction: column;
        }

        .dropdown-right-top {
            margin-bottom: 30px;
        }

        /* 一级菜单标题 */
        .primary-menu-title {
            color: white;
            font-size: 28px;
            font-weight: 700;
            margin-bottom: 5px;
            letter-spacing: 1px;
        }

        .primary-menu-subtitle {
            color: var(--secondary);
            font-size: 16px;
            font-weight: 500;
        }

        /* 二级菜单列表 */
        .submenu-list {
            display: flex;
            flex-wrap: wrap;
            gap: 15px;
        }

        .submenu-list a {
            color: rgba(255, 255, 255, 0.9);
            font-size: 18px;
            font-weight: 600;
            padding: 12px 20px;
            transition: all 0.3s;
            display: block;
            border: 1px solid rgba(255, 255, 255, 0.15);
            border-radius: 4px;
            min-width: 180px;
            text-align: left;
            background-color: rgba(255, 255, 255, 0.05);
            letter-spacing: 0.5px;
        }

        .submenu-list a:hover {
            color: white;
            background-color: rgba(255, 255, 255, 0.1);
            border-color: var(--secondary);
            transform: translateY(-3px);
            box-shadow: 0 5px 15px rgba(212, 175, 55, 0.2);
        }

        /* ==================== 语言切换下拉菜单 ==================== */
        .language-switcher {
            position: relative;
            display: flex;
            align-items: center;
        }

        .language-dropdown {
            position: relative;
            display: inline-block;
        }

        .language-current {
            background: transparent;
            color: var(--primary);
            border: 1px solid #ddd;
            padding: 8px 30px 8px 15px;
            border-radius: 4px;
            cursor: pointer;
            font-weight: 600;
            transition: all 0.3s;
            display: flex;
            align-items: center;
            justify-content: space-between;
            min-width: 100px;
            position: relative;
            font-size: 14px;
        }

        .language-current:hover {
            border-color: var(--secondary);
            color: var(--secondary);
        }

        .language-current i {
            position: absolute;
            right: 10px;
            top: 50%;
            transform: translateY(-50%);
            font-size: 12px;
            transition: transform 0.3s;
            color: #666;
        }

        .language-dropdown.active .language-current i {
            transform: translateY(-50%) rotate(180deg);
        }

        .language-list {
            position: absolute;
            top: 100%;
            right: 0;
            background-color: white;
            border-radius: 4px;
            box-shadow: 0 5px 20px rgba(0, 0, 0, 0.1);
            min-width: 120px;
            display: none;
            z-index: 1001;
            overflow: hidden;
            border: 1px solid #eee;
            margin-top: 5px;
        }

        .language-dropdown.active .language-list {
            display: block;
        }

        .language-option {
            padding: 10px 15px;
            color: #555;
            cursor: pointer;
            transition: all 0.2s;
            border-bottom: 1px solid #f5f5f5;
            display: block;
            font-size: 14px;
            text-align: left;
        }

        .language-option:last-child {
            border-bottom: none;
        }

        .language-option:hover {
            background-color: #f9f9f9;
            color: var(--primary);
        }

        .language-option.active {
            color: var(--primary);
            font-weight: 600;
            background-color: #f0f7ff;
        }

        /* ==================== 移动端菜单按钮 ==================== */
        .mobile-menu-btn {
            display: none;
            background: none;
            border: none;
            font-size: 30px;
            cursor: pointer;
            color: var(--primary);
            margin-left: 30px;
            margin-right: 30px;
        }

        /* ==================== 联系我们页面特定样式 ==================== */
        .contact-hero {
            background: linear-gradient(135deg, var(--primary) 0%, #1e4a7a 100%);
            color: white;
            padding: 80px 0;
            text-align: center;
        }

        .contact-section {
            padding: 80px 0;
        }

        .contact-card {
            background: white;
            border-radius: 12px;
            box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
            padding: 40px;
            transition: transform 0.3s ease, box-shadow 0.3s ease;
        }

        .contact-card:hover {
            transform: translateY(-5px);
            box-shadow: 0 20px 40px rgba(0, 0, 0, 0.15);
        }

        .contact-info-item {
            display: flex;
            align-items: flex-start;
            margin-bottom: 30px;
            padding: 20px;
            background: #f8f9fa;
            border-radius: 8px;
            transition: all 0.3s ease;
        }

        .contact-info-item:hover {
            background: #e9ecef;
            transform: translateX(5px);
        }

        .contact-icon {
            width: 60px;
            height: 60px;
            background: var(--primary);
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            margin-right: 20px;
            flex-shrink: 0;
        }

        .contact-icon i {
            font-size: 24px;
            color: white;
        }

        .contact-details h4 {
            color: var(--primary);
            margin-bottom: 5px;
            font-weight: 600;
        }

        .contact-details p {
            color: #666;
            margin-bottom: 5px;
        }

        .map-container {
            border-radius: 12px;
            overflow: hidden;
            box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
            height: 400px;
        }

        .form-group {
            margin-bottom: 25px;
        }

        .form-label {
            display: block;
            margin-bottom: 8px;
            font-weight: 600;
            color: var(--primary);
        }

        .form-control {
            width: 100%;
            padding: 12px 15px;
            border: 2px solid #e9ecef;
            border-radius: 8px;
            font-size: 16px;
            transition: all 0.3s ease;
        }

        .form-control:focus {
            outline: none;
            border-color: var(--primary);
            box-shadow: 0 0 0 3px rgba(15, 52, 96, 0.1);
        }

        .btn-primary {
            background: var(--primary);
            color: white;
            border: none;
            padding: 15px 30px;
            border-radius: 8px;
            font-size: 16px;
            font-weight: 600;
            cursor: pointer;
            transition: all 0.3s ease;
            width: 100%;
        }

        .btn-primary:hover {
            background: #0d2b4d;
            transform: translateY(-2px);
        }

        .department-card {
            background: white;
            border-radius: 12px;
            padding: 30px;
            box-shadow: 0 5px 15px rgba(0, 0, 0, 0.08);
            transition: all 0.3s ease;
            height: 100%;
        }

        .department-card:hover {
            transform: translateY(-5px);
            box-shadow: 0 15px 30px rgba(0, 0, 0, 0.15);
        }

        .department-icon {
            width: 70px;
            height: 70px;
            background: linear-gradient(135deg, var(--primary), #1e4a7a);
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            margin: 0 auto 20px;
        }

        .department-icon i {
            font-size: 28px;
            color: white;
        }

        /* ==================== 响应式设计 ==================== */
        @media (max-width: 768px) {
            .mobile-menu-btn {
                display: block;
            }

            .main-nav {
                position: absolute;
                top: 100%;
                left: 0;
                width: 100%;
                background: white;
                box-shadow: 0 5px 10px rgba(0,0,0,0.1);
                display: none;
            }

            .main-nav.active {
                display: block;
            }

            .main-nav ul {
                flex-direction: column;
                align-items: stretch;
            }

            .main-nav ul li {
                margin: 0;
                border-bottom: 1px solid #eee;
            }

            .main-nav ul li a {
                padding: 15px;
                display: block;
            }

            .contact-hero {
                padding: 60px 0;
            }

            .contact-section {
                padding: 60px 0;
            }

            .contact-card {
                padding: 25px;
            }

            .contact-info-item {
                flex-direction: column;
                text-align: center;
            }

            .contact-icon {
                margin-right: 0;
                margin-bottom: 15px;
            }
        }