/* CSS Document */

        :root {
            --primary: #2c3e50;
            --secondary: #3498db;
            --accent: #e74c3c;
            --light: #ecf0f1;
            --dark: #2c3e50;
            --success: #2ecc71;
            --warning: #f39c12;
            --gradient: linear-gradient(135deg, var(--secondary), var(--primary));
            --shadow: 0 10px 30px rgba(0,0,0,0.1);
            --radius: 12px;
        }
        
        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
        }
        
        body {
            background-color: #f9fafb;
            color: #333;
            line-height: 1.7;
        }
        
        .container {
            max-width: 1200px;
            margin: 0 auto;
            padding: 0 20px;
        }
        
        /* 头部样式 */
        header {
            background: var(--gradient);
            color: white;
            padding: 60px 0 40px;
            text-align: center;
            position: relative;
            overflow: hidden;
        }
        
        header::before {
            position: absolute;
            top: 0;
            left: 0;
            right: 0;
            bottom: 0;
            background: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100" preserveAspectRatio="none"><path d="M0,0 L100,0 L100,100 Z" fill="rgba(255,255,255,0.05)"/></svg>');
            background-size: 100% 100%;
        }
        
        .logo {
            font-size: 2.8rem;
            font-weight: 800;
            margin-bottom: 15px;
            position: relative;
            display: inline-block;
        }
        
        .logo::after {
            content: '';
            position: absolute;
            bottom: -10px;
            left: 50%;
            transform: translateX(-50%);
            width: 80px;
            height: 4px;
            background: var(--accent);
            border-radius: 2px;
        }
        
        .subtitle {
            font-size: 1.3rem;
            opacity: 0.9;
            max-width: 800px;
            margin: 0 auto;
            font-weight: 300;
        }
        
        /* 导航样式 */
        nav {
            background-color: white;
            box-shadow: var(--shadow);
            position: sticky;
            top: 0;
            z-index: 1000;
        }
        
        .nav-container {
            display: flex;
            justify-content: center;
            flex-wrap: wrap;
        }
        
        .nav-item {
            padding: 18px 25px;
            text-decoration: none;
            color: var(--dark);
            font-weight: 600;
            transition: all 0.3s ease;
            position: relative;
        }
        
        .nav-item:hover {
            color: var(--secondary);
        }
        
        .nav-item::after {
            content: '';
            position: absolute;
            bottom: 0;
            left: 50%;
            transform: translateX(-50%);
            width: 0;
            height: 3px;
            background: var(--secondary);
            transition: width 0.3s ease;
        }
        
        .nav-item:hover::after {
            width: 70%;
        }
        
        /* 内容区域样式 */
        .section {
            padding: 80px 0;
            margin-bottom: 30px;
            border-radius: var(--radius);
        }
        
        .section-title {
            text-align: center;
            color: var(--primary);
            margin-bottom: 60px;
            font-size: 2.4rem;
            position: relative;
            font-weight: 700;
        }
        
        .section-title::after {
            content: '';
            display: block;
            width: 80px;
            height: 5px;
            background: var(--gradient);
            margin: 20px auto;
            border-radius: 3px;
        }
        
        /* 课程模块卡片样式 */
        .modules-grid {
            display: grid;
            grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
            gap: 30px;
            margin-top: 40px;
        }
        
        .module-card {
            background: white;
            border-radius: var(--radius);
            overflow: hidden;
            box-shadow: var(--shadow);
            transition: all 0.4s ease;
            position: relative;
        }
        
        .module-card:hover {
            transform: translateY(-10px);
            box-shadow: 0 15px 35px rgba(0,0,0,0.15);
        }
        
        .module-header {
            background: var(--gradient);
            color: white;
            padding: 25px;
            text-align: center;
            position: relative;
        }
        
        .module-body {
            padding: 25px;
        }
        
        .module-title {
            font-size: 1.5rem;
            margin-bottom: 15px;
            font-weight: 600;
        }
        
        .gift-tag {
            background-color: var(--accent);
            color: white;
            padding: 4px 12px;
            border-radius: 20px;
            font-size: 0.85rem;
            display: inline-block;
            margin-left: 12px;
            font-weight: 500;
        }
        
        /* 特色样式 */
        .feature-list {
            list-style-type: none;
            margin: 25px 0;
        }
        
        .feature-list li {
            padding: 12px 0;
            border-bottom: 1px dashed #eee;
            display: flex;
            align-items: center;
            transition: all 0.3s ease;
        }
        
        .feature-list li:hover {
            background-color: #f8f9fa;
            padding-left: 10px;
        }
        
        .feature-list li:before {
            color: var(--success);
            font-weight: bold;
            margin-right: 12px;
            font-size: 1.2rem;
        }
        
        /* 产品卡片样式 */
        .products-container {
            display: grid;
            grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
            gap: 30px;
            margin-top: 40px;
        }
        
        .product-card {
            background: white;
            border-radius: var(--radius);
            overflow: hidden;
            box-shadow: var(--shadow);
            transition: all 0.4s ease;
            position: relative;
        }
        
        .product-card:hover {
            transform: translateY(-8px);
            box-shadow: 0 15px 35px rgba(0,0,0,0.15);
        }
        
        .product-badge {
            position: absolute;
            top: 15px;
            right: 15px;
            background: var(--accent);
            color: white;
            padding: 5px 12px;
            border-radius: 20px;
            font-size: 0.8rem;
            font-weight: 600;
            z-index: 2;
        }
        
        .product-header {
            background: var(--gradient);
            color: white;
            padding: 25px;
            text-align: center;
        }
        
        .product-body {
            padding: 25px;
        }
        
        .product-title {
            font-size: 1.4rem;
            margin-bottom: 15px;
            font-weight: 600;
            color: var(--primary);
        }
        
        .product-price {
            font-size: 1.8rem;
            color: var(--accent);
            font-weight: 700;
            margin: 20px 0;
            text-align: center;
        }
        
        .product-desc {
            color: #666;
            margin-bottom: 25px;
            font-size: 0.95rem;
        }
        
        .product-features {
            list-style-type: none;
            margin-bottom: 25px;
        }
        
        .product-features li {
            padding: 8px 0;
            display: flex;
            align-items: center;
        }
        
        .product-features li:before {
            color: var(--secondary);
            font-weight: bold;
            margin-right: 10px;
            font-size: 1.2rem;
        }
        
        .btn-group {
            display: flex;
            gap: 12px;
            margin-top: 20px;
        }
        
        .btn {
            display: inline-block;
            padding: 12px 25px;
            border-radius: 50px;
            text-decoration: none;
            font-weight: 600;
            transition: all 0.3s ease;
            text-align: center;
            flex: 1;
            border: none;
            cursor: pointer;
            font-size: 1rem;
        }
        
        .btn-primary {
            background: var(--gradient);
            color: white;
        }
        
        .btn-primary:hover {
            opacity: 0.9;
            transform: translateY(-3px);
            box-shadow: 0 5px 15px rgba(0,0,0,0.1);
        }
        
        .btn-secondary {
            background: white;
            color: var(--secondary);
            border: 2px solid var(--secondary);
        }
        
        .btn-secondary:hover {
            background: var(--secondary);
            color: white;
            transform: translateY(-3px);
            box-shadow: 0 5px 15px rgba(0,0,0,0.1);
        }
        
        /* 联系表单样式 */
        .contact-form {
            background-color: white;
            padding: 40px;
            border-radius: var(--radius);
            margin-top: 40px;
            box-shadow: var(--shadow);
        }
        
        .form-group {
            margin-bottom: 25px;
        }
        
        .form-group label {
            display: block;
            margin-bottom: 10px;
            font-weight: 600;
            color: var(--dark);
        }
        
        .form-group input, .form-group textarea, .form-group select {
            width: 100%;
            padding: 15px;
            border: 1px solid #ddd;
            border-radius: 8px;
            font-size: 1rem;
            transition: all 0.3s ease;
        }
        
        .form-group input:focus, .form-group textarea:focus, .form-group select:focus {
            border-color: var(--secondary);
            box-shadow: 0 0 0 3px rgba(52, 152, 219, 0.2);
            outline: none;
        }
        
        .form-group textarea {
            height: 140px;
            resize: vertical;
        }
        
        .submit-btn {
            background: var(--gradient);
            color: white;
            border: none;
            padding: 15px 30px;
            border-radius: 50px;
            font-size: 1.1rem;
            font-weight: 600;
            cursor: pointer;
            transition: all 0.3s ease;
            display: block;
            width: 100%;
            margin-top: 20px;
        }
        
        .submit-btn:hover {
            opacity: 0.9;
            transform: translateY(-3px);
            box-shadow: 0 5px 15px rgba(0,0,0,0.1);
        }
        
        /* 联系信息样式 */
        .contact-info {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
            gap: 25px;
            margin-top: 50px;
        }
        
        .contact-card {
            background: white;
            padding: 30px;
            border-radius: var(--radius);
            box-shadow: var(--shadow);
            text-align: center;
            transition: all 0.3s ease;
        }
        
        .contact-card:hover {
            transform: translateY(-5px);
            box-shadow: 0 15px 35px rgba(0,0,0,0.1);
        }
        
        .contact-card h3 {
            color: var(--primary);
            margin-bottom: 20px;
            font-size: 1.4rem;
        }
        
        .contact-card p {
            margin-bottom: 10px;
            color: #555;
        }
        
        .contact-icon {
            font-size: 2.5rem;
            color: var(--secondary);
            margin-bottom: 20px;
        }
        
        /* 页脚样式 */
        footer {
            background-color: var(--dark);
            color: white;
            padding: 50px 0 30px;
            text-align: center;
            margin-top: 80px;
        }
        
        .footer-content {
            display: flex;
            flex-direction: column;
            align-items: center;
        }
        
        .footer-logo {
            font-size: 2rem;
            font-weight: 700;
            margin-bottom: 20px;
        }
        
        .footer-links {
            display: flex;
            gap: 25px;
            margin: 30px 0;
        }
        
        .footer-link {
            color: #ddd;
            text-decoration: none;
            transition: all 0.3s ease;
        }
        
        .footer-link:hover {
            color: white;
            text-decoration: underline;
        }
        
        .copyright {
            margin-top: 30px;
            color: #aaa;
            font-size: 0.9rem;
        }
        
        /* 响应式设计 */
        @media (max-width: 992px) {
            .modules-grid, .products-container {
                grid-template-columns: 1fr;
            }
            
            .nav-container {
                flex-wrap: wrap;
            }
            
            .section {
                padding: 60px 0;
            }
            
            .btn-group {
                flex-direction: column;
            }
        }
        
        @media (max-width: 768px) {
            .logo {
                font-size: 2.2rem;
            }
            
            .subtitle {
                font-size: 1.1rem;
            }
            
            .section-title {
                font-size: 2rem;
            }
            
            .contact-info {
                grid-template-columns: 1fr;
            }
            
            .contact-form {
                padding: 25px;
            }
            
            .nav-item {
                padding: 15px;
                font-size: 0.9rem;
            }
        }