:root {
            --primary-color: #1a5276;
            --secondary-color: #2e86c1;
            --accent-color: #3498db;
            --light-blue: #85c1e9;
            --text-color: #333333;
            --light-text: #666666;
            --background-color: #ffffff;
            --card-bg: #f8f9fa;
            --border-color: #e0e0e0;
            --shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
        }

        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }
        
        body {
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
            line-height: 1.6;
            background-color: var(--background-color);
            color: var(--text-color);
        }
        
        header {
            background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
            padding: 3rem 0 2rem;
            text-align: center;
            color: white;
            position: relative;
            overflow: hidden;
        }

        header::before {
            content: "";
            position: absolute;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 1440 320"><path fill="%23ffffff" fill-opacity="0.1" d="M0,96L48,112C96,128,192,160,288,186.7C384,213,480,235,576,213.3C672,192,768,128,864,128C960,128,1056,192,1152,192C1248,192,1344,128,1392,96L1440,64L1440,320L1392,320C1344,320,1248,320,1152,320C1056,320,960,320,864,320C768,320,672,320,576,320C480,320,384,320,288,320C192,320,96,320,48,320L0,320Z"></path></svg>');
            background-size: cover;
            background-position: bottom;
        }
        
        .header-content {
            position: relative;
            z-index: 1;
            max-width: 1200px;
            margin: 0 auto;
            padding: 0 2rem;
        }
        
        h1 {
            font-size: 2.8rem;
            margin-bottom: 0.5rem;
            font-weight: 700;
        }
        
        .subtitle {
            font-size: 1.3rem;
            opacity: 0.9;
            margin-bottom: 1.5rem;
            font-weight: 300;
        }
        
        nav {
            background-color: white;
            padding: 1rem 0;
            position: sticky;
            top: 0;
            z-index: 100;
            box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
        }
        
        nav ul {
            display: flex;
            justify-content: center;
            list-style: none;
            max-width: 1200px;
            margin: 0 auto;
            flex-wrap: wrap;
        }
        
        nav li {
            margin: 0 1rem;
        }
        
        nav a {
            color: var(--text-color);
            text-decoration: none;
            font-weight: 600;
            padding: 0.7rem 1.2rem;
            border-radius: 30px;
            transition: all 0.3s ease;
            display: flex;
            align-items: center;
        }
        
        nav a i {
            margin-right: 8px;
            font-size: 1.1rem;
        }

        nav a:hover, nav a.active {
            background-color: var(--light-blue);
            color: var(--primary-color);
        }
        
        .container {
            max-width: 1200px;
            margin: 0 auto;
            padding: 3rem 2rem;
        }
        
        section {
            margin-bottom: 3rem;
            padding: 2.5rem;
            background-color: var(--card-bg);
            border-radius: 12px;
            box-shadow: var(--shadow);
            border: 1px solid var(--border-color);
            transition: transform 0.3s ease;
        }
        
        section:hover {
            transform: translateY(-5px);
        }
        
        h2 {
            color: var(--primary-color);
            margin-bottom: 1.5rem;
            padding-bottom: 0.8rem;
            border-bottom: 2px solid var(--light-blue);
            display: flex;
            align-items: center;
        }
        
        h2 i {
            margin-right: 12px;
            font-size: 1.8rem;
        }
        
        h3 {
            color: var(--secondary-color);
            margin: 1.5rem 0 1rem;
            display: flex;
            align-items: center;
        }
        
        h3 i {
            margin-right: 10px;
            font-size: 1.3rem;
        }
        
        .section-intro {
            margin-bottom: 1.5rem;
            color: var(--light-text);
            line-height: 1.8;
        }
        
        .module-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
            gap: 2rem;
            margin-top: 2rem;
        }
        
        .module-card {
            background-color: white;
            padding: 2rem;
            border-radius: 10px;
            transition: all 0.3s ease;
            border: 1px solid var(--border-color);
            display: flex;
            flex-direction: column;
            height: 100%;
        }
        
        .module-card:hover {
            transform: translateY(-5px);
            box-shadow: 0 8px 16px rgba(0, 0, 0, 0.1);
        }
        
       .module-card h3 {
            margin-bottom: 1rem;
            color: var(--secondary-color);
            display: flex;
            align-items: center;
        }
        
        .module-card h3 i {
            margin-right: 10px;
            font-size: 1.5rem;
        }
        
        .module-card p {
            color: var(--light-text);
            flex-grow: 1;
            margin-bottom: 1.5rem;
        }
        
        .module-link {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            background: linear-gradient(to right, var(--secondary-color), var(--accent-color));
            color: white;
            padding: 0.8rem 1.5rem;
            border-radius: 30px;
            text-decoration: none;
            font-weight: 600;
            transition: all 0.3s ease;
            align-self: flex-start;
        }
        
        .module-link:hover {
            transform: translateY(-2px);
            box-shadow: 0 5px 15px rgba(52, 152, 219, 0.4);
        }
        
        .module-link i {
            margin-right: 8px;
        }
        
        .back-link {
            display: inline-flex;
            align-items: center;
            color: var(--secondary-color);
            text-decoration: none;
            font-weight: 600;
            margin-bottom: 1.5rem;
            transition: all 0.3s ease;
        }
        
        .back-link:hover {
            color: var(--primary-color);
        }
        
        .back-link i {
            margin-right: 8px;
        }
        
        .content-section {
            margin-bottom: 2.5rem;
            padding: 2rem;
            background-color: white;
            border-radius: 10px;
            border: 1px solid var(--border-color);
            box-shadow: var(--shadow);
        }
        
        /* .content-section:last-child {
            border-bottom: none;
        }
        
        .content-section h3 {
            color: #1e3c72;
            margin-bottom: 1rem;
            display: flex;
            align-items: center;
            font-size: 1.4rem;
        }
        
        .content-section h3 i {
            margin-right: 0.5rem;
        } */
        
        .download-btn {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            background: linear-gradient(to right, var(--secondary-color), var(--accent-color));
            color: white;
            padding: 0.7rem 1.3rem;
            border-radius: 30px;
            text-decoration: none;
            font-weight: 600;
            transition: all 0.3s ease;
            margin-top: 1rem;
            font-size: 0.9rem;
        }
        
        .download-btn:hover {
            transform: translateY(-2px);
            box-shadow: 0 5px 15px rgba(52, 152, 219, 0.4);
        }
        
        .download-btn i {
            margin-right: 8px;
        }
        
        .contact-info {
            display: flex;
            justify-content: center;
            margin: 1.5rem 0;
            flex-wrap: wrap;
        }
        
        .contact-item {
            margin: 0 1.5rem;
            display: flex;
            align-items: center;
        }
        
        .contact-item i {
            margin-right: 8px;
            font-size: 1.2rem;
        }
        
        footer {
            background-color: var(--primary-color);
            color: white;
            text-align: center;
            padding: 2.5rem 0;
            margin-top: 3rem;
        }
        
        .footer-content {
            max-width: 1200px;
            margin: 0 auto;
            padding: 0 2rem;
        }
        
        .copyright {
            margin-top: 1.5rem;
            opacity: 0.8;
            font-size: 0.9rem;
        }
        
        /* .icon-large {
            font-size: 3rem;
            color: #1e3c72;
            margin-bottom: 1rem;
        } */
        
        @media (max-width: 768px) {
            nav ul {
                flex-direction: column;
                align-items: center;
            }
            
            nav li {
                margin: 0.3rem 0;
                width: 100%;
                text-align: center;
            }
            
            nav a {
                justify-content: center;
            }
            
            .module-grid {
                grid-template-columns: 1fr;
            }
            
            .contact-info {
                flex-direction: column;
                align-items: center;
            }
            
            .contact-item {
                margin: 0.5rem 0;
            }
            
            h1 {
                font-size: 2.2rem;
            }
            
            .subtitle {
                font-size: 1.1rem;
            }
        }

        .icon-large {
            font-size: 3rem;
            color: var(--primary-color);
            margin-bottom: 1rem;
            text-align: center;
            display: block;
        }

        .module-page {
            display: block;
        }

        /* 确保所有页面元素正常显示 */
        #home-page, #model-page {
            min-height: 100vh;
            display: flex;
            flex-direction: column;
        }

        .container {
            flex: 1;
        }