:root {
            --primary: #4361ee;
            --primary-light: #4895ef;
            --secondary: #3f37c9;
            --success: #4cc9f0;
            --danger: #f72585;
            --warning: #f8961e;
            --light: #f8f9fa;
            --dark: #212529;
            --gray: #6c757d;
            --border-radius: 12px;
            --shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
            --transition: all 0.3s ease;
        }
        
        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            font-family: "Noto Sans SC", sans-serif;
        }
        
        body {
            background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
            color: var(--dark);
            line-height: 1.6;
            min-height: 100vh;
        }
        
        /* 导航栏样式 */
        .navbar {
            background: white;
            box-shadow: var(--shadow);
            position: sticky;
            top: 0;
            z-index: 100;
        }
        
        .nav-container {
            max-width: 1200px;
            margin: 0 auto;
            padding: 0 20px;
            display: flex;
            justify-content: space-between;
            align-items: center;
            height: 70px;
        }
        
        .logo {
            display: flex;
            align-items: center;
            font-size: 1.5rem;
            font-weight: 700;
            color: var(--primary);
            text-decoration: none;
        }
        
        .logo i {
            margin-right: 10px;
            font-size: 1.8rem;
        }
        
        .nav-links {
            display: flex;
            list-style: none;
        }
        
        .nav-links li {
            margin-left: 30px;
        }
        
        .nav-links a {
            text-decoration: none;
            color: var(--dark);
            font-weight: 500;
            transition: var(--transition);
            padding: 8px 0;
            position: relative;
        }
        
        .nav-links a:hover {
            color: var(--primary);
        }
        
        .nav-links a::after {
            content: '';
            position: absolute;
            bottom: 0;
            left: 0;
            width: 0;
            height: 2px;
            background: var(--primary);
            transition: var(--transition);
        }
        
        .nav-links a:hover::after {
            width: 100%;
        }
        
        .nav-links a.active {
            color: var(--primary);
        }
        
        .nav-links a.active::after {
            width: 100%;
        }
        
        .mobile-menu {
            display: none;
            font-size: 1.5rem;
            cursor: pointer;
        }
        
        /* 英雄区域样式 */
        .hero {
            padding: 100px 20px;
            text-align: center;
            max-width: 800px;
            margin: 0 auto;
        }
        
        .hero h1 {
            font-size: 3rem;
            margin-bottom: 20px;
            color: var(--dark);
            line-height: 1.2;
        }
        
        .hero p {
            font-size: 1.2rem;
            color: var(--gray);
            margin-bottom: 40px;
        }
        
        .hero-buttons {
            display: flex;
            justify-content: center;
            gap: 20px;
            flex-wrap: wrap;
        }
        
        .btn {
            display: inline-flex;
            align-items: center;
            padding: 14px 30px;
            border-radius: 50px;
            font-weight: 600;
            text-decoration: none;
            transition: var(--transition);
            font-size: 1.1rem;
            box-shadow: var(--shadow);
        }
        
        .btn i {
            margin-right: 10px;
        }
        
        .btn-primary {
            background: linear-gradient(to right, var(--primary), var(--secondary));
            color: white;
        }
        
        .btn-primary:hover {
            transform: translateY(-3px);
            box-shadow: 0 6px 12px rgba(67, 97, 238, 0.3);
        }
        
        .btn-secondary {
            background: white;
            color: var(--primary);
            border: 2px solid var(--primary);
        }
        
        .btn-secondary:hover {
            background: var(--primary);
            color: white;
            transform: translateY(-3px);
        }
        
        /* 特性区域样式 */
        .features {
            padding: 80px 20px;
            background: white;
        }
        
        .section-title {
            text-align: center;
            margin-bottom: 60px;
        }
        
        .section-title h2 {
            font-size: 2.5rem;
            color: var(--dark);
            margin-bottom: 15px;
        }
        
        .section-title p {
            color: var(--gray);
            max-width: 600px;
            margin: 0 auto;
        }
        
        .features-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
            gap: 30px;
            max-width: 1200px;
            margin: 0 auto;
        }
        
        .feature-card {
            background: var(--light);
            border-radius: var(--border-radius);
            padding: 30px;
            text-align: center;
            transition: var(--transition);
            box-shadow: 0 4px 6px rgba(0,0,0,0.05);
        }
        
        .feature-card:hover {
            transform: translateY(-10px);
            box-shadow: 0 10px 20px rgba(0,0,0,0.1);
        }
        
        .feature-icon {
            width: 80px;
            height: 80px;
            background: linear-gradient(to right, var(--primary), var(--secondary));
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            margin: 0 auto 20px;
            color: white;
            font-size: 2rem;
        }
        
        .feature-card h3 {
            font-size: 1.5rem;
            margin-bottom: 15px;
            color: var(--dark);
        }
        
        .feature-card p {
            color: var(--gray);
        }
        
        /* 测试类型区域样式 */
        .test-types {
            padding: 80px 20px;
            background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
        }
        
        .test-cards {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
            gap: 30px;
            max-width: 1200px;
            margin: 0 auto;
        }
        
        .test-card {
            background: white;
            border-radius: var(--border-radius);
            overflow: hidden;
            box-shadow: var(--shadow);
            transition: var(--transition);
        }
        
        .test-card:hover {
            transform: translateY(-10px);
            box-shadow: 0 15px 30px rgba(0,0,0,0.15);
        }
        
        .test-card-header {
            background: linear-gradient(to right, var(--primary), var(--secondary));
            color: white;
            padding: 25px;
            text-align: center;
        }
        
        .test-card-header h3 {
            font-size: 1.8rem;
            margin-bottom: 10px;
        }
        
        .test-card-body {
            padding: 30px;
        }
        
        .test-card-body ul {
            list-style: none;
            margin-bottom: 25px;
        }
        
        .test-card-body li {
            padding: 10px 0;
            border-bottom: 1px solid #eee;
            display: flex;
            align-items: center;
        }
        
        .test-card-body li i {
            color: var(--primary);
            margin-right: 10px;
        }
        
        .test-card-body li:last-child {
            border-bottom: none;
        }
        
        .test-card-footer {
            padding: 0 30px 30px;
            text-align: center;
        }
        
        /* 页脚样式 */
        .footer {
            background: var(--dark);
            color: white;
            padding: 60px 20px 30px;
        }
        
        .footer-content {
            max-width: 1200px;
            margin: 0 auto;
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
            gap: 40px;
            margin-bottom: 40px;
        }
        
        .footer-column h4 {
            font-size: 1.3rem;
            margin-bottom: 20px;
            color: white;
        }
        
        .footer-links {
            list-style: none;
        }
        
        .footer-links li {
            margin-bottom: 10px;
        }
        
        .footer-links a {
            color: #adb5bd;
            text-decoration: none;
            transition: var(--transition);
        }
        
        .footer-links a:hover {
            color: white;
        }
        
        .footer-bottom {
            max-width: 1200px;
            margin: 0 auto;
            padding-top: 30px;
            border-top: 1px solid #495057;
            text-align: center;
            color: #adb5bd;
        }
        
        /* 响应式设计 */
        @media (max-width: 768px) {
            .nav-links {
                display: none;
                position: absolute;
                top: 70px;
                left: 0;
                width: 100%;
                background: white;
                flex-direction: column;
                padding: 20px;
                box-shadow: 0 10px 10px rgba(0,0,0,0.1);
            }
            
            .nav-links.active {
                display: flex;
            }
            
            .nav-links li {
                margin: 10px 0;
            }
            
            .mobile-menu {
                display: block;
            }
            
            .hero h1 {
                font-size: 2.2rem;
            }
            
            .hero p {
                font-size: 1.1rem;
            }
            
            .test-cards {
                grid-template-columns: 1fr;
            }
            
            .section-title h2 {
                font-size: 2rem;
            }
        }
        
        @media (max-width: 480px) {
            .hero {
                padding: 60px 20px;
            }
            
            .hero h1 {
                font-size: 1.8rem;
            }
            
            .btn {
                width: 100%;
                justify-content: center;
            }
            
            .hero-buttons {
                flex-direction: column;
            }
        }