/* 通用头部样式 */
        .site-header {
            background: linear-gradient(135deg, #1e5799 0%, #207cca 51%, #2989d8 100%);
            color: white;
            padding: 5px 0;
            box-shadow: 0 2px 10px rgba(0,0,0,0.1);
            width: 100%; /* 确保宽度填满 */
        }
        
        .header-container {
            max-width: 1200px;
            margin: 0 auto;
            display: flex;
            justify-content: space-between;
            align-items: center;
            padding: 0 20px;
        }
        
        .logo {
            font-size: 24px;
            font-weight: bold;
            display: flex;
            align-items: center;
        }
        
        .logo img {
            height: 40px;
            margin-right: 10px;
        }
        
        .main-nav ul {
            display: flex;
            list-style: none;
            margin: 0;
            padding: 0;
        }
        
        .main-nav li {
            margin-left: 25px;
            position: relative;
        }
        
        .main-nav a {
            color: white;
            text-decoration: none;
            font-size: 16px;
            font-weight: 500;
            padding: 5px 0;
            transition: all 0.3s ease;
            border-bottom: 2px solid transparent;
        }
        
        .main-nav a:hover,
        .main-nav a.active {
            border-bottom: 2px solid #fff;
        }
        
        /* 响应式设计 */
        @media (max-width: 768px) {
            .header-container {
                flex-direction: column;
                text-align: center;
            }
            
            .logo {
                margin-bottom: 15px;
            }
            
            .main-nav ul {
                flex-wrap: wrap;
                justify-content: center;
            }
            
            .main-nav li {
                margin: 0 10px 10px;
            }
        }