/* 优化字体栈 */
        @supports (font-variation-settings: normal) {
            body {
                font-family: 'Inter var', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
            }
        }
        
        /* 确保header有明确的定位上下文 */
        header {
            background: var(--bg);
            box-shadow: var(--shadow);
            position: sticky;
            top: 0;
            z-index: 1000;
            backdrop-filter: blur(20px);
            background: rgba(255, 255, 255, 0.95);
        }
        
        .nav-container {
            display: flex;
            justify-content: space-between;
            align-items: center;
            padding: 0 24px;
            height: 72px;
            max-width: 1200px;
            margin: 0 auto;
        }
        
        .logo {
            font-size: 24px;
            font-weight: 700;
            color: var(--primary);
            transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
            letter-spacing: -0.025em;
        }
        
        .logo:hover {
            transform: translateY(-1px);
            text-shadow: 0 2px 4px rgba(0, 102, 255, 0.2);
        }
        
        /* 桌面端导航 - 优化排版 */
        .desktop-nav {
            display: flex;
            list-style: none;
            gap: 8px;
        }
        
        .desktop-nav li {
            position: relative;
        }
        
        .desktop-nav li a {
            color: var(--text);
            text-decoration: none;
            padding: 12px 20px;
            display: block;
            transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
            border-radius: 8px;
            font-weight: 500;
            font-size: 15px;
            letter-spacing: -0.01em;
            position: relative;
            overflow: hidden;
        }
        
        .desktop-nav li a::before {
            content: '';
            position: absolute;
            top: 0;
            left: -100%;
            width: 100%;
            height: 100%;
            background: linear-gradient(90deg, transparent, rgba(0, 102, 255, 0.08), transparent);
            transition: left 0.6s ease;
        }
        
        .desktop-nav li a:hover::before {
            left: 100%;
        }
        
        .desktop-nav li a:hover {
            background: var(--bg-hover);
            color: var(--primary);
            transform: translateY(-1px);
            box-shadow: var(--shadow-hover);
        }
        
        .desktop-nav li a.active {
            background: var(--primary);
            color: white;
            box-shadow: 0 4px 12px rgba(0, 102, 255, 0.3);
        }
        
        /* 优化二级菜单样式 */
        .desktop-submenu {
            position: absolute;
            top: 100%;
            left: 0;
            background: var(--bg);
            border: 1px solid var(--border);
            border-radius: 12px;
            box-shadow: var(--shadow-hover);
            min-width: 240px;
            opacity: 0;
            visibility: hidden;
            transform: translateY(-8px) scale(0.95);
            transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
            z-index: 1001;
            overflow: hidden;
            backdrop-filter: blur(20px);
            background: rgba(255, 255, 255, 0.95);
        }
        
        .desktop-nav li:hover .desktop-submenu {
            opacity: 1;
            visibility: visible;
            transform: translateY(0) scale(1);
        }
        
        .desktop-submenu li {
            border-bottom: 1px solid var(--border);
        }
        
        .desktop-submenu li:last-child {
            border-bottom: none;
        }
        
        .desktop-submenu li a {
            padding: 14px 20px;
            font-size: 14px;
            font-weight: 400;
            color: var(--text);
            transition: all 0.2s ease;
            border-radius: 0;
        }
        
        .desktop-submenu li a:hover {
            background: rgba(0, 102, 255, 0.04);
            color: var(--primary);
            padding-left: 24px;
            transform: none;
            box-shadow: none;
        }
        
        /* 移动端汉堡菜单优化 */
        .mobile-menu-toggle {
            display: none;
            background: none;
            border: none;
            font-size: 24px;
            color: var(--text);
            cursor: pointer;
            padding: 8px 12px;
            border-radius: 8px;
            transition: all 0.3s ease;
            font-weight: 500;
        }
        
        .mobile-menu-toggle:hover {
            background: var(--bg-hover);
            color: var(--primary);
        }
        
        /* 移动端导航菜单位置优化 */
        .mobile-nav {
            display: none;
            position: absolute;
            top: 100%;
            left: 0;
            width: 100%;
            background: var(--bg);
            box-shadow: var(--shadow-hover);
            border-top: 1px solid var(--border);
            z-index: 1001;
            backdrop-filter: blur(20px);
            background: rgba(255, 255, 255, 0.98);
        }
        
        .mobile-nav.active {
            display: block;
        }
        
        .mobile-nav ul {
            list-style: none;
        }
        
        .mobile-nav li {
            border-bottom: 1px solid var(--border);
        }
        
        .mobile-nav li:last-child {
            border-bottom: none;
        }
        
        .mobile-nav li a {
            display: block;
            padding: 16px 24px;
            color: var(--text);
            text-decoration: none;
            transition: all 0.3s ease;
            font-size: 16px;
            font-weight: 500;
        }
        
        .mobile-nav li a:hover {
            background: var(--bg-hover);
            color: var(--primary);
            padding-left: 32px;
        }
        
        /* 移动端子菜单优化 */
        .mobile-submenu {
            display: none;
            background: rgba(0, 102, 255, 0.02);
        }
        
        .mobile-nav li.active .mobile-submenu {
            display: block;
        }
        
        .mobile-submenu li a {
            padding-left: 48px;
            font-size: 15px;
            font-weight: 400;
            color: var(--text-light);
        }
        
        .has-submenu > a::after {
            content: '›';
            float: right;
            transition: transform 0.3s ease;
            font-weight: 600;
        }
        
        .has-submenu.active > a::after {
            transform: rotate(90deg);
        }
        
        /* 720px断点 - 移动端样式优化 */
        @media (max-width: 720px) {
            .nav-container {
                padding: 0 20px;
            }
            
            .desktop-nav {
                display: none;
            }
            
            .mobile-menu-toggle {
                display: block;
            }
            
            .mobile-nav {
                position: absolute;
                top: 100%;
                left: 0;
                width: 100%;
            }
            
            .desktop-submenu {
                display: none;
            }
            
            /* 移动端字体优化 */
            .mobile-nav li a {
                font-size: 16px;
                letter-spacing: -0.01em;
            }
            
            .mobile-submenu li a {
                font-size: 15px;
            }
        }
        
        /* 主要内容区域样式优化 */
        .main-content {
            padding: 48px 24px;
            max-width: 800px;
            margin: 0 auto;
        }
        
        .content-section {
            background: var(--bg);
            border-radius: 16px;
            box-shadow: var(--shadow);
            padding: 32px;
            margin-bottom: 32px;
            transition: all 0.3s ease;
        }
        
        .content-section:hover {
            transform: translateY(-2px);
            box-shadow: var(--shadow-hover);
        }
        
        .content-section h1 {
            color: var(--primary);
            margin-bottom: 24px;
            font-size: 2.5em;
            font-weight: 700;
            line-height: 1.2;
            letter-spacing: -0.025em;
        }
        
        .content-section h2 {
            color: var(--primary);
            margin-bottom: 20px;
            font-size: 1.75em;
            font-weight: 600;
            line-height: 1.3;
            letter-spacing: -0.02em;
        }
        
        .content-section p {
            color: var(--text);
            margin-bottom: 20px;
            line-height: 1.7;
            font-size: 17px;
            font-weight: 400;
        }
        
        .content-section ul {
            color: var(--text);
            margin-bottom: 20px;
            padding-left: 24px;
        }
        
        .content-section li {
            margin-bottom: 12px;
            font-size: 16px;
            line-height: 1.6;
        }
        
        .content-section strong {
            font-weight: 600;
            color: var(--text);
        }
        
        /* 响应式调整 */
        @media (max-width: 768px) {
            .main-content {
                padding: 32px 20px;
            }
            
            .content-section {
                padding: 24px;
                border-radius: 12px;
            }
            
            .content-section h1 {
                font-size: 2em;
            }
            
            .content-section h2 {
                font-size: 1.5em;
            }
            
            .content-section p {
                font-size: 16px;
            }
        }
        
        /* 加载Inter字体 */
        @import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&display=swap');