:root {
            --primary: #229ED9;
            --primary-dark: #1b7fad;
            --secondary: #2AABEE;
            --dark: #17212B;
            --gray-bg: #F4F7FB;
            --border: #E3E8EE;
            --text-main: #222B45;
            --text-muted: #6B7C96;
            --white: #ffffff;
            --success: #00C853;
            --warning: #FF9100;
        }

        * { margin: 0; padding: 0; box-sizing: border-box; }
        html { scroll-behavior: smooth; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif; color: var(--text-main); background-color: var(--gray-bg); line-height: 1.6; }
        a { text-decoration: none; color: inherit; }
        .container { max-width: 1200px; margin: 0 auto; padding: 0 20px; }

        /* 顶部导航 */
        header { background: var(--white); border-bottom: 1px solid var(--border); position: sticky; top: 0; z-index: 100; }
        .nav-wrapper { display: flex; justify-content: space-between; align-items: center; height: 70px; }
        .logo { font-size: 20px; font-weight: bold; color: var(--primary); display: flex; align-items: center; gap: 8px; }
        .nav-menu { display: flex; gap: 24px; list-style: none; font-size: 15px; font-weight: 500; }
        .nav-menu a:hover { color: var(--primary); }
        .nav-btn { background: var(--primary); color: var(--white); padding: 10px 20px; border-radius: 6px; font-weight: bold; transition: 0.2s; min-height: 44px; display: inline-flex; align-items: center; }
        .nav-btn:hover { background: var(--primary-dark); }
        .menu-toggle { display: none; background: none; border: none; font-size: 24px; cursor: pointer; color: var(--primary); padding: 8px; min-width: 44px; min-height: 44px; }

        /* 面包屑导航 */
        .breadcrumb { padding: 12px 0; font-size: 13px; color: var(--text-muted); }
        .breadcrumb ol { list-style: none; display: flex; gap: 6px; }
        .breadcrumb li + li::before { content: ">"; margin-right: 6px; color: #ccc; }
        .breadcrumb a:hover { color: var(--primary); }

        /* Hero 区域 */
        .hero { background: linear-gradient(135deg, #17212B 0%, #0E1621 100%); color: var(--white); padding: 70px 0 60px; text-align: center; }
        .hero h1 { font-size: 32px; margin-bottom: 16px; font-weight: 800; line-height: 1.3; }
        .hero p { font-size: 16px; color: #9AB0C6; max-width: 800px; margin: 0 auto 30px; }
        .hero-features { display: flex; justify-content: center; gap: 16px; flex-wrap: wrap; margin-bottom: 30px; }
        .hero-tag { background: rgba(255,255,255,0.1); padding: 6px 16px; border-radius: 20px; font-size: 14px; border: 1px solid rgba(255,255,255,0.15); }

        /* 通用区块样式 */
        section { padding: 60px 0; }
        .section-header { text-align: center; margin-bottom: 40px; }
        .section-header h2 { font-size: 26px; font-weight: 700; margin-bottom: 10px; position: relative; display: inline-block; }
        .section-header h2::after { content: ""; display: block; width: 50px; height: 3px; background: var(--primary); margin: 8px auto 0; border-radius: 2px; }
        .section-header p { color: var(--text-muted); font-size: 15px; }

        /* 商品矩阵卡片 */
        .product-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: 20px; }
        .product-card { background: var(--white); border: 1px solid var(--border); border-radius: 10px; padding: 24px; display: flex; flex-direction: column; justify-content: space-between; transition: transform 0.2s, box-shadow 0.2s; }
        .product-card:hover { transform: translateY(-4px); box-shadow: 0 12px 24px rgba(0,0,0,0.06); border-color: var(--primary); }
        .product-badge { display: inline-block; padding: 4px 8px; border-radius: 4px; font-size: 12px; font-weight: bold; margin-bottom: 12px; }
        .badge-hot { background: #FFEAEA; color: #FF3B30; }
        .badge-safe { background: #E8F8F0; color: var(--success); }
        .badge-pro { background: #EAF4FE; color: var(--primary); }
        .product-card h3 { font-size: 18px; margin-bottom: 10px; }
        .product-desc { font-size: 13px; color: var(--text-muted); margin-bottom: 16px; min-height: 40px; }
        .product-price { font-size: 20px; font-weight: bold; color: #FF3B30; margin-bottom: 16px; }
        .product-price span { font-size: 13px; color: var(--text-muted); font-weight: normal; }

        /* 购买按钮 - 通用样式（button 重置） */
        .buy-btn {
            display: block;
            width: 100%;
            text-align: center;
            background: var(--primary);
            color: var(--white);
            padding: 12px 0;
            border: none;
            border-radius: 6px;
            font-weight: bold;
            min-height: 44px;
            font-size: 15px;
            font-family: inherit;
            cursor: pointer;
            transition: background 0.2s;
        }
        .buy-btn:hover { background: var(--primary-dark); }
        .buy-btn:active { transform: scale(0.98); }

        /* Hero 区按钮变体 */
        .buy-btn-hero {
            display: inline-block;
            width: auto;
            padding: 12px 36px;
            font-size: 16px;
        }

        /* 教程与指南模块 */
        .tutorial-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(340px, 1fr)); gap: 24px; }
        .guide-card { background: var(--white); border-radius: 10px; padding: 26px; border: 1px solid var(--border); }
        .guide-card h3 { font-size: 18px; color: var(--dark); margin-bottom: 14px; display: flex; align-items: center; gap: 8px; }
        .guide-card h3::before { content: "✔"; color: var(--primary); font-weight: bold; }
        .guide-card ol, .guide-card ul { padding-left: 20px; font-size: 14px; color: #4A5568; }
        .guide-card li { margin-bottom: 8px; }

        /* FAQ 常见问题折叠样式 */
        .faq-wrapper { max-width: 900px; margin: 0 auto; display: flex; flex-direction: column; gap: 14px; }
        .faq-item { background: var(--white); border-radius: 8px; border: 1px solid var(--border); overflow: hidden; }
        .faq-question { padding: 18px 24px; font-size: 16px; font-weight: 600; cursor: pointer; display: flex; justify-content: space-between; align-items: center; margin: 0; }
        .faq-question:hover { color: var(--primary); }
        .faq-answer { padding: 0 24px 18px; font-size: 14px; color: #4A5568; border-top: 1px solid #F0F4F8; padding-top: 14px; }

        /* 防骗与选购建议 */
        .buyer-tips-box { background: #FFF9E6; border: 1px solid #FFE082; border-radius: 8px; padding: 24px; max-width: 900px; margin: 0 auto 30px; }
        .buyer-tips-box h3 { font-size: 17px; color: #D97706; margin-bottom: 10px; }

        /* 页脚 */
        footer { background: var(--dark); color: #8A9BA8; padding: 40px 0 20px; font-size: 13px; }
        .footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr; gap: 40px; margin-bottom: 30px; }
        .footer-col h4 { color: var(--white); font-size: 15px; margin-bottom: 12px; }
        .footer-col p { margin-bottom: 10px; line-height: 1.5; }
        .footer-bottom { border-top: 1px solid #2C3847; padding-top: 20px; text-align: center; font-size: 12px; }

        @media (max-width: 768px) {
            .nav-menu { display: none; }
            .nav-menu.active { display: flex; flex-direction: column; position: absolute; top: 70px; left: 0; right: 0; background: #fff; padding: 20px; box-shadow: 0 4px 12px rgba(0,0,0,0.1); }
            .menu-toggle { display: block; }
            .hero h1 { font-size: 24px; }
            .footer-grid { grid-template-columns: 1fr; gap: 20px; }
        }