/* 全局变量与重置 */
        :root {
            --primary: #1a365d;
            --secondary: #c53030;
            --accent: #2b6cb0;
            --light: #f7fafc;
            --dark: #2d3748;
            --gray: #718096;
            --success: #38a169;
            --border: #e2e8f0;
            --radius: 12px;
            --shadow: 0 10px 25px rgba(0, 0, 0, 0.05);
            --shadow-hover: 0 15px 35px rgba(0, 0, 0, 0.1);
        }
        
        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }
        
        body {
            font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
            line-height: 1.7;
            color: var(--dark);
            background: linear-gradient(135deg, #f5f7fa 0%, #f0f4f8 100%);
            overflow-x: hidden;
        }
        
        .container {
            max-width: 1200px;
            margin: 0 auto;
            padding: 0 20px;
        }
        
        /* 顶部导航栏 */
        .top-bar {
            background: white;
            box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
           /* position: sticky;*/
            top: 0;
            z-index: 1000;
        }
        
        .nav-container {
            display: flex;
            justify-content: space-between;
            align-items: center;
            padding: 20px 0;
        }
        
        .brand {
            display: flex;
            align-items: center;
            gap: 12px;
        }
        
        .brand-logo {
            font-size: 28px;
            font-weight: 900;
            color: var(--primary);
            background: linear-gradient(135deg, var(--primary), var(--accent));
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            letter-spacing: -0.5px;
        }
        
        .brand-subtitle {
            font-size: 12px;
            color: var(--gray);
            font-weight: 500;
        }
        
        .main-nav {
            display: flex;
            gap: 30px;
        }
        
        .nav-item {
            text-decoration: none;
            color: var(--dark);
            font-weight: 600;
            font-size: 16px;
            position: relative;
            padding: 5px 0;
        }
        
        .nav-item::after {
            content: '';
            position: absolute;
            width: 0;
            height: 3px;
            bottom: 0;
            left: 0;
            background: var(--secondary);
            transition: width 0.3s ease;
            border-radius: 2px;
        }
        
        .nav-item:hover::after {
            width: 100%;
        }
        
        .nav-item.active {
            color: var(--secondary);
        }
        
        /* 英雄区域 */
        .hero-section {
            padding: 100px 0 80px;
            position: relative;
            overflow: hidden;
        }
        
        .hero-background {
            position: absolute;
            top: 0;
            right: 0;
            width: 60%;
            height: 100%;
            background: linear-gradient(135deg, rgba(26, 54, 93, 0.05) 0%, rgba(43, 108, 176, 0.05) 100%);
            border-radius: 0 0 0 100px;
            z-index: -1;
        }
        
        .hero-content {
            max-width: 800px;
        }
        
        .hero-title {
            font-size: 48px;
            font-weight: 800;
            color: var(--primary);
            line-height: 1.2;
            margin-bottom: 20px;
            letter-spacing: -0.5px;
        }
        
        .hero-subtitle {
            font-size: 20px;
            color: var(--gray);
            margin-bottom: 40px;
            max-width: 700px;
        }
        
        .highlight {
            background: linear-gradient(120deg, rgba(197, 48, 48, 0.15) 0%, rgba(197, 48, 48, 0) 100%);
            padding: 2px 6px;
            border-radius: 4px;
            font-weight: 700;
        }
        
        /* 按钮样式 */
        .btn {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            padding: 16px 32px;
            font-weight: 700;
            text-decoration: none;
            border-radius: var(--radius);
            transition: all 0.3s ease;
            border: none;
            cursor: pointer;
            font-size: 16px;
            gap: 10px;
        }
        
        .btn-primary {
            background: linear-gradient(135deg, var(--secondary), #e53e3e);
            color: white;
            box-shadow: 0 6px 20px rgba(197, 48, 48, 0.25);
        }
        
        .btn-primary:hover {
            transform: translateY(-3px);
            box-shadow: 0 12px 25px rgba(197, 48, 48, 0.3);
        }
        
        .btn-outline {
            background: transparent;
            color: var(--primary);
            border: 2px solid var(--primary);
        }
        
        .btn-outline:hover {
            background: var(--primary);
            color: white;
        }
        
        /* 卡片设计 */
        .card {
            background: white;
            border-radius: var(--radius);
            padding: 40px;
            box-shadow: var(--shadow);
            transition: all 0.3s ease;
            height: 100%;
        }
        
        .card:hover {
            transform: translateY(-10px);
            box-shadow: var(--shadow-hover);
        }
        
        .card-header {
            display: flex;
            align-items: center;
            gap: 15px;
            margin-bottom: 25px;
        }
        
        .card-icon {
            width: 60px;
            height: 60px;
            background: linear-gradient(135deg, var(--primary), var(--accent));
            border-radius: 12px;
            display: flex;
            align-items: center;
            justify-content: center;
            color: white;
            font-size: 24px;
            font-weight: 700;
        }
        
        .card-title {
            font-size: 24px;
            font-weight: 700;
            color: var(--primary);
            margin-bottom: 5px;
        }
        
        .card-subtitle {
            color: var(--gray);
            font-size: 14px;
        }
        
        /* 标签样式 */
        .tag {
            display: inline-block;
            padding: 6px 15px;
            background: var(--light);
            color: var(--primary);
            border-radius: 20px;
            font-size: 12px;
            font-weight: 700;
            margin-right: 10px;
            margin-bottom: 10px;
        }
        
        .tag-primary {
            background: rgba(26, 54, 93, 0.1);
            color: var(--primary);
        }
        
        .tag-secondary {
            background: rgba(197, 48, 48, 0.1);
            color: var(--secondary);
        }
        
        .tag-accent {
            background: rgba(43, 108, 176, 0.1);
            color: var(--accent);
        }
        
        /* 网格布局 */
        .grid {
            display: grid;
            gap: 30px;
        }
        
        .grid-2 {
            grid-template-columns: repeat(2, 1fr);
        }
        
        .grid-3 {
            grid-template-columns: repeat(3, 1fr);
        }
        
        .grid-4 {
            grid-template-columns: repeat(4, 1fr);
        }
        
        /* 章节样式 */
        .section {
            padding: 80px 0;
        }
        
        .section-header {
            text-align: center;
            margin-bottom: 60px;
        }
        
        .section-title {
            font-size: 36px;
            font-weight: 800;
            color: var(--primary);
            margin-bottom: 15px;
            letter-spacing: -0.5px;
        }
        
        .section-subtitle {
            font-size: 18px;
            color: var(--gray);
            max-width: 700px;
            margin: 0 auto;
        }
        
        /* 特色区块 */
        .feature-block {
            background: linear-gradient(135deg, rgba(26, 54, 93, 0.03) 0%, rgba(43, 108, 176, 0.03) 100%);
            border-radius: var(--radius);
            padding: 30px;
            margin: 30px 0;
            border-left: 5px solid var(--secondary);
        }
        
        /* 比较表格 */
        .comparison-wrapper {
            background: white;
            border-radius: var(--radius);
            overflow: hidden;
            box-shadow: var(--shadow);
        }
        
        .comparison-header {
            display: grid;
            grid-template-columns: 1fr 1fr 1fr;
            background: var(--primary);
            color: white;
            font-weight: 700;
            text-align: center;
        }
        
        .comparison-header div {
            padding: 25px;
            font-size: 18px;
        }
        
        .comparison-row {
            display: grid;
            grid-template-columns: 1fr 1fr 1fr;
            border-bottom: 1px solid var(--border);
            transition: background 0.2s ease;
        }
        
        .comparison-row:hover {
            background: var(--light);
        }
        
        .comparison-row div {
            padding: 20px;
            display: flex;
            align-items: center;
        }
        
        .comparison-row .row-label {
            font-weight: 600;
            color: var(--primary);
            background: var(--light);
        }
        
        /* 流程步骤 */
        .process-steps {
            counter-reset: step-counter;
            position: relative;
        }
        
        .process-steps::before {
            content: '';
            position: absolute;
            top: 40px;
            left: 40px;
            bottom: 40px;
            width: 3px;
            background: var(--border);
            z-index: 1;
        }
        
        .process-step {
            display: flex;
            gap: 30px;
            margin-bottom: 50px;
            position: relative;
            z-index: 2;
        }
        
        .step-number {
            width: 80px;
            height: 80px;
            background: white;
            border: 3px solid var(--primary);
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 32px;
            font-weight: 800;
            color: var(--primary);
            flex-shrink: 0;
            position: relative;
        }
        
        .step-content {
            flex: 1;
            padding-top: 15px;
        }
        
        .step-title {
            font-size: 22px;
            font-weight: 700;
            color: var(--primary);
            margin-bottom: 10px;
        }
        
        /* 常见问题 */
        .faq-container {
            max-width: 900px;
            margin: 0 auto;
        }
        
        .faq-item {
            background: white;
            border-radius: var(--radius);
            margin-bottom: 20px;
            overflow: hidden;
            box-shadow: var(--shadow);
        }
        
        .faq-question {
            padding: 25px 30px;
            font-weight: 700;
            font-size: 18px;
            color: var(--primary);
            cursor: pointer;
            display: flex;
            justify-content: space-between;
            align-items: center;
        }
        
        .faq-answer {
            padding: 0 30px 25px;
            color: var(--gray);
            border-top: 1px solid var(--border);
        }
        
        /* 热门话题按钮 */
        .topic-buttons {
            display: grid;
            grid-template-columns: repeat(4, 1fr);
            gap: 20px;
            margin-top: 40px;
        }
        
        .topic-button {
            background: white;
            border: 2px solid var(--border);
            border-radius: var(--radius);
            padding: 25px 15px;
            text-align: center;
            text-decoration: none;
            color: var(--primary);
            font-weight: 700;
            transition: all 0.3s ease;
            display: flex;
            flex-direction: column;
            align-items: center;
            gap: 10px;
        }
        
        .topic-button:hover {
            border-color: var(--secondary);
            transform: translateY(-5px);
            box-shadow: var(--shadow-hover);
        }
        
        .topic-icon {
            width: 50px;
            height: 50px;
            background: var(--light);
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 20px;
            color: var(--secondary);
        }
        
        /* 页脚 */
        .footer {
            background: var(--primary);
            color: white;
            padding: 70px 0 30px;
            margin-top: 80px;
        }
        
        .footer-grid {
            display: grid;
            grid-template-columns: repeat(4, 1fr);
            gap: 40px;
            margin-bottom: 50px;
        }
        
        .footer-title {
            font-size: 18px;
            font-weight: 700;
            margin-bottom: 25px;
            color: white;
        }
        
        .footer-links a {
            display: block;
            color: rgba(255, 255, 255, 0.7);
            text-decoration: none;
            margin-bottom: 12px;
            transition: color 0.2s ease;
        }
        
        .footer-links a:hover {
            color: white;
        }
        
        .copyright {
            text-align: center;
            padding-top: 30px;
            border-top: 1px solid rgba(255, 255, 255, 0.1);
            color: rgba(255, 255, 255, 0.6);
            font-size: 14px;
        }
        
        /* 响应式设计 */
        @media (max-width: 1024px) {
            .grid-2, .grid-3, .grid-4 {
                grid-template-columns: repeat(2, 1fr);
            }
            
            .footer-grid {
                grid-template-columns: repeat(2, 1fr);
            }
            
            .topic-buttons {
                grid-template-columns: repeat(2, 1fr);
            }
        }
        
        @media (max-width: 768px) {
            .nav-container {
                flex-direction: column;
                gap: 20px;
            }
            
            .main-nav {
                flex-wrap: wrap;
                justify-content: center;
                gap: 15px;
            }
            
            .hero-title {
                font-size: 36px;
            }
            
            .grid-2, .grid-3, .grid-4 {
                grid-template-columns: 1fr;
            }
            
            .comparison-header, .comparison-row {
                grid-template-columns: 1fr;
            }
            
            .comparison-header div, .comparison-row div {
                padding: 15px;
            }
            
            .comparison-row .row-label {
                background: transparent;
                font-weight: 700;
                font-size: 18px;
                color: var(--primary);
                border-bottom: 2px solid var(--border);
            }
            
            .footer-grid {
                grid-template-columns: 1fr;
            }
            
            .topic-buttons {
                grid-template-columns: 1fr;
            }
            
            .process-steps::before {
                display: none;
            }
            
            .process-step {
                flex-direction: column;
                align-items: center;
                text-align: center;
            }
        }
        
        @media (max-width: 480px) {
            .hero-title {
                font-size: 28px;
            }
            
            .section-title {
                font-size: 28px;
            }
            
            .card {
                padding: 25px;
            }
            
            .btn {
                padding: 14px 25px;
                font-size: 14px;
            }
        }