:root {
            --primary: #2563eb;
            --primary-dark: #1d4ed8;
            --secondary: #0ea5e9;
            --light: #f0f9ff;
            --dark: #1e293b;
            --accent: #f59e0b;
            --gray: #64748b;
            --light-gray: #f1f5f9;
            --font-family: "Noto Sans SC", "仿宋", "FangSong", serif;
        }
        
        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }
        
        body {
            font-family: var(--font-family);
            line-height: 1.8;
            color: var(--dark);
            background-color: #ffffff;
        }
        
        .container {
            width: 100%;
            max-width: 1200px;
            margin: 0 auto;
            padding: 0 1.5rem;
        }
        
        /* 导航栏样式 */
        header {
            background: white;
            box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
            position: fixed;
            width: 100%;
            top: 0;
            z-index: 1000;
        }
        
        .navbar {
            display: flex;
            justify-content: space-between;
            align-items: center;
            padding: 1rem 0;
        }
        
        .logo {
            font-size: 1.5rem;
            font-weight: 700;
            color: var(--primary);
            text-decoration: none;
            display: flex;
            align-items: center;
        }
        
        .logo i {
            margin-right: 0.5rem;
            font-size: 1.8rem;
        }
        
        .nav-links {
            display: flex;
            list-style: none;
        }
        
        .nav-links li {
            margin-left: 2rem;
        }
        
        .nav-links a {
            color: var(--dark);
            text-decoration: none;
            font-weight: 500;
            transition: color 0.3s ease;
        }
        
        .nav-links a:hover {
            color: var(--primary);
        }
        
        .nav-links a.active {
            color: var(--primary);
            border-bottom: 2px solid var(--primary);
        }
        
        /* 英雄区域样式 */
        .hero {
            background: linear-gradient(135deg, var(--light) 0%, #e6f0ff 100%);
            padding: 8rem 0 6rem;
            margin-top: 70px;
            position: relative;
            overflow: hidden;
        }
        
        .hero::before {
            content: '';
            position: absolute;
            top: 0;
            right: 0;
            width: 50%;
            height: 100%;
            background-image: url('../webimage/csbg.jpg');
            background-size: cover;
            background-position: center;
            opacity: 0.1;
            z-index: 0;
        }
        
        .hero-content {
            position: relative;
            z-index: 1;
            max-width: 700px;
        }
        
        .hero h1 {
            font-size: 2.5rem;
            margin-bottom: 1.5rem;
            color: var(--primary-dark);
        }
        
        .hero p {
            font-size: 1.1rem;
            color: var(--gray);
            margin-bottom: 2rem;
        }
        
        .btn {
            display: inline-block;
            background-color: var(--primary);
            color: white;
            padding: 0.8rem 1.5rem;
            border-radius: 6px;
            text-decoration: none;
            font-weight: 500;
            transition: all 0.3s ease;
            border: none;
            cursor: pointer;
        }
        
        .btn:hover {
            background-color: var(--primary-dark);
            transform: translateY(-2px);
            box-shadow: 0 4px 12px rgba(37, 99, 235, 0.25);
        }
        
        /* 内容区域通用样式 */
        .section {
            padding: 6rem 0;
        }
        
        .section-title {
            text-align: center;
            margin-bottom: 4rem;
        }
        
        .section-title h2 {
            font-size: 2rem;
            color: var(--dark);
            position: relative;
            display: inline-block;
            padding-bottom: 1rem;
        }
        
        .section-title h2:after {
            content: '';
            position: absolute;
            left: 50%;
            bottom: 0;
            transform: translateX(-50%);
            width: 60px;
            height: 4px;
            background: var(--accent);
        }
        
        /* 竞赛介绍样式 */
        .intro-grid {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 3rem;
            align-items: center;
        }
        
        .intro-content {
            padding-right: 2rem;
        }
        
        .intro-content h3 {
            font-size: 1.5rem;
            margin-bottom: 1.5rem;
            color: var(--primary);
        }
        
        .intro-content p {
            margin-bottom: 1rem;
            color: var(--gray);
        }
        
        .intro-image {
            border-radius: 10px;
            overflow: hidden;
            box-shadow: 0 10px 25px rgba(0, 0, 0, 0.08);
        }
        
        .intro-image img {
            width: 100%;
            height: auto;
            display: block;
            transition: transform 0.5s ease;
        }
        
        .intro-image:hover img {
            transform: scale(1.03);
        }
        
        /* 级别体系样式 */
        .levels-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
            gap: 2rem;
        }
        
        .level-card {
            background: white;
            border-radius: 10px;
            padding: 2rem;
            box-shadow: 0 5px 15px rgba(0, 0, 0, 0.05);
            transition: all 0.3s ease;
            border-top: 4px solid var(--primary);
        }
        
        .level-card:hover {
            transform: translateY(-5px);
            box-shadow: 0 15px 30px rgba(0, 0, 0, 0.1);
        }
        
        .level-card.bronze {
            border-top-color: #cd7f32;
        }
        
        .level-card.silver {
            border-top-color: #c0c0c0;
        }
        
        .level-card.gold {
            border-top-color: #ffd700;
        }
        
        .level-card.platinum {
            border-top-color: #e5e4e2;
        }
        
        .level-card h3 {
            font-size: 1.3rem;
            margin-bottom: 1rem;
            display: flex;
            align-items: center;
        }
        
        .level-card h3 i {
            margin-right: 0.5rem;
            font-size: 1.5rem;
        }
        
        .level-card ul {
            list-style: none;
            margin-top: 1rem;
        }
        
        .level-card ul li {
            padding: 0.5rem 0;
            display: flex;
            align-items: flex-start;
        }
        
        .level-card ul li i {
            color: var(--primary);
            margin-right: 0.5rem;
            margin-top: 0.5rem;
        }
        
        .level-card .level-link {
            display: inline-block;
            margin-top: 1.5rem;
            color: var(--primary);
            text-decoration: none;
            font-weight: 500;
        }
        
        .level-card .level-link:hover {
            color: var(--primary-dark);
            text-decoration: underline;
        }
        
        /* 课程优势样式 */
        .features-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
            gap: 2rem;
        }
        
        .feature-box {
            text-align: center;
            padding: 2rem 1.5rem;
            background: var(--light);
            border-radius: 10px;
            transition: all 0.3s ease;
        }
        
        .feature-box:hover {
            background: white;
            box-shadow: 0 10px 25px rgba(0, 0, 0, 0.05);
        }
        
        .feature-box i {
            font-size: 2.5rem;
            color: var(--primary);
            margin-bottom: 1.5rem;
        }
        
        .feature-box h3 {
            margin-bottom: 1rem;
            font-size: 1.3rem;
        }
        
        /* 常见问题样式 */
        .faq-item {
            margin-bottom: 1.5rem;
            border: 1px solid var(--light-gray);
            border-radius: 6px;
            overflow: hidden;
        }
        
        .faq-question {
            width: 100%;
            text-align: left;
            background: white;
            padding: 1rem 1.5rem;
            border: none;
            font-family: var(--font-family);
            font-size: 1rem;
            font-weight: 500;
            display: flex;
            justify-content: space-between;
            align-items: center;
            cursor: pointer;
        }
        
        .faq-question i {
            transition: transform 0.3s ease;
        }
        
        .faq-question.active i {
            transform: rotate(180deg);
        }
        
        .faq-answer {
            padding: 0 1.5rem;
            max-height: 0;
            overflow: hidden;
            transition: all 0.3s ease;
            background: var(--light-gray);
        }
        
        .faq-answer.active {
            padding: 1.5rem;
            max-height: 500px;
        }
        
        /* 页脚样式 */
        footer {
            background: var(--dark);
            color: white;
            padding: 4rem 0 2rem;
        }
        
        .footer-content {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
            gap: 3rem;
            margin-bottom: 3rem;
        }
        
        .footer-col h3 {
            font-size: 1.2rem;
            margin-bottom: 1.5rem;
            color: var(--accent);
        }
        
        .footer-col ul {
            list-style: none;
        }
        
        .footer-col ul li {
            margin-bottom: 0.8rem;
        }
        
        .footer-col a {
            color: #b9c3cd;
            text-decoration: none;
            transition: color 0.3s ease;
        }
        
        .footer-col a:hover {
            color: white;
        }
        
        .copyright {
            text-align: center;
            padding-top: 2rem;
            border-top: 1px solid rgba(255, 255, 255, 0.1);
            color: #b9c3cd;
            font-size: 0.9rem;
        }
        
        /* 响应式设计 */
        @media (max-width: 768px) {
            .nav-links {
                display: none;
            }
            
            .hero h1 {
                font-size: 2rem;
            }
            
            .intro-grid {
                grid-template-columns: 1fr;
            }
            
            .intro-content {
                padding-right: 0;
                margin-bottom: 2rem;
            }
            
            .section {
                padding: 4rem 0;
            }
        }