body {
            font-family: Arial, sans-serif;
            margin: 0;
            padding: 0;
            background-color: #f5f5f5;
            color: #333;
        }
        
        /* 导航栏样式 */
        .nav {
            background-color: #333;
            color: white;
            padding: 15px 0;
            box-shadow: 0 2px 4px rgba(0,0,0,0.1);
            position: sticky;
            top: 0;
            z-index: 1000;
        }
        
        .nav .container {
            max-width: 1200px;
            margin: 0 auto;
            padding: 0 20px;
            display: flex;
            flex-direction: column;
            align-items: center;
            gap: 15px;
        }
        
        .nav-logo {
            font-size: 28px;
            font-weight: bold;
            color: white;
            text-decoration: none;
            margin-bottom: 10px;
            display: block;
        }
        
        .nav-links {
            display: flex;
            list-style: none;
            margin: 0;
            padding: 0;
            flex-wrap: wrap;
            justify-content: center;
        }
        
        .nav-links li {
            margin: 0 15px;
        }
        
        .nav-links a {
            color: white;
            text-decoration: none;
            font-size: 16px;
            transition: color 0.3s ease;
        }
        
        .nav-links a:hover {
            color: #2196F3;
        }
        
        /* 英雄区域样式 */
        .hero {
            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            color: white;
            padding: 100px 0;
            text-align: center;
        }
        
        .hero .container {
            max-width: 1200px;
            margin: 0 auto;
            padding: 0 20px;
        }
        
        .hero h1 {
            font-size: 48px;
            margin-bottom: 20px;
            font-weight: bold;
        }
        
        .hero p {
            font-size: 20px;
            margin-bottom: 40px;
            opacity: 0.9;
        }
        
        .hero .btn {
            display: inline-block;
            background-color: white;
            color: #667eea;
            padding: 15px 30px;
            text-decoration: none;
            border-radius: 50px;
            font-size: 18px;
            font-weight: bold;
            transition: all 0.3s ease;
            margin: 0 10px;
        }
        
        .hero .btn:hover {
            background-color: #f5f5f5;
            transform: translateY(-2px);
            box-shadow: 0 4px 12px rgba(0,0,0,0.15);
        }
        
        .hero .btn-primary {
            background-color: #2196F3;
            color: white;
        }
        
        /* 功能介绍区域样式 */
        .features {
            padding: 80px 0;
            background-color: white;
        }
        
        .features .container {
            max-width: 1200px;
            margin: 0 auto;
            padding: 0 20px;
        }
        
        .features h2 {
            text-align: center;
            font-size: 36px;
            margin-bottom: 60px;
            color: #333;
        }
        
        .features-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
            gap: 40px;
        }
        
        .feature-item {
            text-align: center;
            padding: 30px;
            border-radius: 10px;
            box-shadow: 0 2px 10px rgba(0,0,0,0.08);
            transition: transform 0.3s ease, box-shadow 0.3s ease;
        }
        
        .feature-item:hover {
            transform: translateY(-5px);
            box-shadow: 0 5px 20px rgba(0,0,0,0.1);
        }
        
        .feature-item .icon {
            font-size: 48px;
            margin-bottom: 20px;
            color: #667eea;
        }
        
        .feature-item h3 {
            font-size: 24px;
            margin-bottom: 15px;
            color: #333;
        }
        
        .feature-item p {
            color: #666;
            line-height: 1.6;
        }
        
        /* 页脚样式 */
        .footer {
            background-color: #333;
            color: white;
            text-align: center;
            padding: 30px 0;
        }
        
        .footer .container {
            max-width: 1200px;
            margin: 0 auto;
            padding: 0 20px;
        }
        
        /* 下拉菜单样式 */
        .dropdown {
            position: relative;
            display: inline-block;
        }
        
        .dropdown-btn {
            background: none;
            border: none;
            color: white;
            font-size: 16px;
            cursor: pointer;
            display: flex;
            align-items: center;
            gap: 5px;
            padding: 0;
        }
        
        .dropdown-content {
            display: none;
            position: absolute;
            right: 0;
            background-color: white;
            min-width: 160px;
            box-shadow: 0 8px 16px rgba(0,0,0,0.1);
            z-index: 1001;
            border-radius: 5px;
            overflow: hidden;
        }
        
        .dropdown-content a {
            color: #333;
            padding: 12px 16px;
            text-decoration: none;
            display: block;
            text-align: left;
        }
        
        .dropdown-content a:hover {
            background-color: #f5f5f5;
        }
        
        /* 显示下拉菜单 */
        .dropdown:hover .dropdown-content {
            display: block;
        }
        
        /* 下拉菜单分割线 */
        .dropdown-divider {
            height: 1px;
            background-color: #eee;
            margin: 8px 0;
        }
        
        /* 响应式设计 */
        @media (max-width: 768px) {
            .nav .container {
                flex-direction: column;
                gap: 10px;
            }
            
            .nav-links {
                flex-wrap: wrap;
                justify-content: center;
            }
            
            .nav-links li {
                margin: 0 10px;
            }
            
            .hero h1 {
                font-size: 36px;
            }
            
            .hero p {
                font-size: 18px;
            }
            
            .hero .btn {
                margin: 10px 0;
                display: block;
                width: 80%;
                margin: 10px auto;
            }
        }