* {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }

        body {
            font-family: system-ui, -apple-system, 'Segoe UI', Roboto, 'Helvetica Neue', Helvetica, sans-serif;
            background-color: #ffffff;
            color: #111111;
            line-height: 1.5;
            scroll-behavior: smooth;
        }

        .container {
            max-width: 1280px;
            margin: 0 auto;
            padding: 0 24px;
        }

        /* header 与首页一致 */
        .header {
            background-color: #ffffff;
            border-bottom: 1px solid #e5e7eb;
            position: sticky;
            top: 0;
            z-index: 50;
        }

        .nav {
            display: flex;
            justify-content: space-between;
            align-items: center;
            flex-wrap: wrap;
            padding: 18px 0;
        }

        .logo {
            font-size: 1.8rem;
            font-weight: 700;
            letter-spacing: -0.02em;
            background: linear-gradient(135deg, #25D366, #128C7E);
            -webkit-background-clip: text;
            background-clip: text;
            color: transparent;
            text-decoration: none;
        }

        .nav-links {
            display: flex;
            gap: 32px;
            align-items: center;
            list-style: none;
        }

        .nav-links a {
            text-decoration: none;
            font-weight: 500;
            color: #1f2937;
            transition: color 0.2s;
            font-size: 1rem;
        }

        .nav-links a:hover {
            color: #25D366;
        }

        .nav-links .active {
            color: #128C7E;
            font-weight: 600;
        }

        .btn-outline {
            border: 1px solid #25D366;
            background: transparent;
            padding: 8px 20px;
            border-radius: 40px;
            font-weight: 600;
            color: #128C7E;
            transition: all 0.2s;
            text-decoration: none;
            cursor: pointer;
        }

        .btn-outline:hover {
            background: #25D36610;
            border-color: #128C7E;
        }

        .btn-primary {
            display: inline-block;
            background-color: #25D366;
            color: white;
            font-weight: 600;
            padding: 12px 32px;
            border-radius: 40px;
            text-decoration: none;
            transition: background 0.2s, transform 0.1s;
            border: none;
            font-size: 1rem;
            cursor: pointer;
        }

        .btn-primary:hover {
            background-color: #128C7E;
        }

        /* 页面标题区 */
        .page-hero {
            background: linear-gradient(145deg, #f0fdf6 0%, #f9fafb 50%, #ffffff 100%);
            padding: 64px 0 48px;
            text-align: center;
            border-bottom: 1px solid #d4f5e2;
        }

        .page-hero .shield-icon {
            font-size: 3.5rem;
            margin-bottom: 12px;
            display: block;
        }

        .page-hero h1 {
            font-size: 2.7rem;
            font-weight: 800;
            letter-spacing: -0.02em;
            background: linear-gradient(135deg, #1f2b3c, #075e54);
            -webkit-background-clip: text;
            background-clip: text;
            color: transparent;
            margin-bottom: 16px;
        }

        .page-hero .subtitle {
            font-size: 1.15rem;
            color: #4b5563;
            max-width: 720px;
            margin: 0 auto;
            line-height: 1.7;
        }

        .section-title {
            font-size: 2rem;
            font-weight: 700;
            margin-bottom: 16px;
            text-align: center;
        }

        .section-desc {
            color: #4b5563;
            max-width: 700px;
            margin: 0 auto 48px;
            font-size: 1.05rem;
            text-align: center;
            line-height: 1.6;
        }

        /* 加密体系区块 */
        .crypto-section {
            padding: 80px 0;
        }

        .crypto-flow {
            display: flex;
            flex-wrap: wrap;
            gap: 24px;
            justify-content: center;
            margin-top: 40px;
        }

        .crypto-step {
            background: #fff;
            border: 2px solid #eef2f6;
            border-radius: 24px;
            padding: 32px 24px;
            text-align: center;
            flex: 1;
            min-width: 180px;
            max-width: 240px;
            transition: all 0.25s;
            position: relative;
        }

        .crypto-step:hover {
            border-color: #25D366;
            box-shadow: 0 12px 28px -8px rgba(37, 211, 102, 0.18);
            transform: translateY(-4px);
        }

        .crypto-step .cs-icon {
            font-size: 2.6rem;
            margin-bottom: 14px;
        }

        .crypto-step h4 {
            font-weight: 700;
            margin-bottom: 8px;
            font-size: 1.1rem;
        }

        .crypto-step p {
            font-size: 0.9rem;
            color: #6b7280;
            line-height: 1.5;
        }

        .crypto-arrow {
            display: flex;
            align-items: center;
            font-size: 1.6rem;
            color: #25D366;
            font-weight: 700;
            flex-shrink: 0;
            padding: 0 4px;
        }

        /* 技术详情卡片 */
        .tech-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
            gap: 28px;
            margin-top: 40px;
        }

        .tech-card {
            background: #f9fafb;
            border-radius: 24px;
            padding: 32px 28px;
            border: 1px solid #edf2f7;
            transition: 0.2s;
        }

        .tech-card:hover {
            border-color: #cbf0da;
            box-shadow: 0 8px 24px -8px rgba(0, 0, 0, 0.06);
            background: #fdfdfd;
        }

        .tech-card .tc-icon {
            font-size: 2.2rem;
            margin-bottom: 14px;
        }

        .tech-card h3 {
            font-weight: 700;
            font-size: 1.3rem;
            margin-bottom: 10px;
        }

        .tech-card p {
            color: #4b5563;
            font-size: 0.95rem;
            line-height: 1.65;
        }

        .tech-card .highlight-tag {
            display: inline-block;
            background: #e9f9ef;
            color: #075e54;
            padding: 4px 12px;
            border-radius: 14px;
            font-size: 0.78rem;
            font-weight: 600;
            margin-top: 12px;
        }

        /* 同步架构图 */
        .sync-architecture {
            background: #f9fafb;
            border-radius: 32px;
            padding: 48px 36px;
            margin: 0 0 80px;
            text-align: center;
            border: 1px solid #eef2f6;
        }

        .sync-architecture h3 {
            font-size: 1.8rem;
            font-weight: 700;
            margin-bottom: 24px;
        }

        .sync-visual {
            display: flex;
            flex-wrap: wrap;
            gap: 32px;
            align-items: center;
            justify-content: center;
        }

        .sync-node {
            background: #fff;
            border-radius: 20px;
            padding: 24px 22px;
            border: 2px solid #e5e7eb;
            text-align: center;
            min-width: 140px;
            transition: 0.2s;
        }

        .sync-node.master {
            border-color: #25D366;
            background: #f0fdf6;
            box-shadow: 0 0 0 6px rgba(37, 211, 102, 0.08);
        }

        .sync-node .node-icon {
            font-size: 2.4rem;
            margin-bottom: 8px;
        }

        .sync-node .node-label {
            font-weight: 700;
            font-size: 0.95rem;
        }

        .sync-node .node-desc {
            font-size: 0.78rem;
            color: #6b7280;
            margin-top: 4px;
        }

        .sync-connector {
            font-size: 1.8rem;
            color: #25D366;
            font-weight: 700;
            flex-shrink: 0;
        }

        /* 下载模块 */
        .creative-downloads {
            background: linear-gradient(135deg, #f0fdf6, #f9fafb);
            border-radius: 32px;
            padding: 48px 40px;
            margin: 0 0 80px;
            border: 1px solid #d4f5e2;
        }

        .download-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
            gap: 28px;
            margin-top: 32px;
        }

        .download-card {
            background: #fff;
            border-radius: 20px;
            padding: 30px 22px;
            text-align: center;
            border: 2px solid #edf2f7;
            transition: all 0.25s;
            text-decoration: none;
            color: inherit;
            display: block;
            cursor: pointer;
        }

        .download-card:hover {
            border-color: #25D366;
            box-shadow: 0 16px 32px -10px rgba(37, 211, 102, 0.22);
            transform: translateY(-4px);
        }

        .download-icon {
            font-size: 2.8rem;
            margin-bottom: 12px;
        }

        .download-card h4 {
            font-weight: 700;
            margin-bottom: 6px;
            font-size: 1.1rem;
        }

        .download-card p {
            font-size: 0.88rem;
            color: #6b7280;
            line-height: 1.5;
        }

        .download-card .dl-tag {
            display: inline-block;
            margin-top: 10px;
            padding: 5px 16px;
            border-radius: 20px;
            font-size: 0.78rem;
            font-weight: 600;
            background: #e9f9ef;
            color: #075e54;
        }

        /* FAQ */
        .faq-section {
            padding: 0 0 80px;
        }

        .faq-list {
            max-width: 800px;
            margin: 0 auto;
        }

        .faq-list details {
            background: #f9fafb;
            border-radius: 16px;
            padding: 20px 28px;
            margin-bottom: 12px;
            border: 1px solid #edf2f7;
            cursor: pointer;
            transition: all 0.2s;
        }

        .faq-list details:hover {
            border-color: #cbf0da;
            background: #fdfdfd;
        }

        .faq-list summary {
            font-weight: 600;
            font-size: 1.05rem;
            color: #1f2b3c;
            list-style: none;
            display: flex;
            justify-content: space-between;
            align-items: center;
        }

        .faq-list summary::-webkit-details-marker {
            display: none;
        }

        .faq-list summary::after {
            content: '+';
            font-size: 1.4rem;
            color: #25D366;
            font-weight: 700;
            transition: transform 0.2s;
        }

        .faq-list details[open] summary::after {
            content: '−';
            color: #128C7E;
        }

        .faq-list .faq-answer {
            margin-top: 14px;
            color: #4b5563;
            line-height: 1.7;
            padding-top: 12px;
            border-top: 1px solid #eef2f6;
        }

        /* 内链 */
        .inner-links {
            display: flex;
            flex-wrap: wrap;
            gap: 20px;
            justify-content: center;
            margin: 0 0 56px;
        }

        .inner-link-card {
            background: #fff;
            border: 1px solid #e5e7eb;
            border-radius: 16px;
            padding: 16px 28px;
            text-decoration: none;
            font-weight: 600;
            color: #1f2937;
            display: inline-flex;
            align-items: center;
            gap: 8px;
            transition: 0.2s;
        }

        .inner-link-card:hover {
            border-color: #25D366;
            background: #f0fdf4;
        }

        /* 安全徽章区 */
        .trust-badges {
            display: flex;
            flex-wrap: wrap;
            gap: 20px;
            justify-content: center;
            margin: 48px 0 16px;
        }

        .trust-badge {
            background: #fff;
            border: 1px solid #e5e7eb;
            border-radius: 40px;
            padding: 10px 22px;
            font-weight: 600;
            font-size: 0.9rem;
            color: #1f2b3c;
            display: flex;
            align-items: center;
            gap: 8px;
            transition: 0.2s;
        }

        .trust-badge:hover {
            border-color: #25D366;
            background: #fafffe;
        }

        .trust-badge .badge-dot {
            width: 8px;
            height: 8px;
            border-radius: 50%;
            background: #25D366;
            flex-shrink: 0;
        }

        /* footer 与首页一致 */
        .footer {
            border-top: 1px solid #eaeef3;
            padding: 48px 0 32px;
            background: #fafcff;
        }

        .footer-grid {
            display: flex;
            flex-wrap: wrap;
            justify-content: space-between;
            gap: 32px;
            margin-bottom: 40px;
        }

        .footer-col {
            min-width: 140px;
        }

        .footer-col h4 {
            font-weight: 600;
            margin-bottom: 18px;
            color: #111827;
        }

        .footer-col ul {
            list-style: none;
        }

        .footer-col li {
            margin-bottom: 12px;
        }

        .footer-col a {
            text-decoration: none;
            color: #4b5563;
            font-size: 0.9rem;
        }

        .footer-col a:hover {
            color: #128C7E;
        }

        .copyright {
            text-align: center;
            padding-top: 28px;
            border-top: 1px solid #e5e7eb;
            font-size: 0.8rem;
            color: #6c757d;
        }

        @media (max-width: 768px) {
            .nav {
                flex-direction: column;
                gap: 16px;
            }
            .nav-links {
                flex-wrap: wrap;
                justify-content: center;
                gap: 20px;
            }
            .page-hero h1 {
                font-size: 2rem;
            }
            .crypto-arrow {
                transform: rotate(90deg);
                padding: 8px 0;
            }
            .crypto-flow {
                flex-direction: column;
                align-items: center;
            }
            .crypto-step {
                max-width: 100%;
            }
            .sync-visual {
                flex-direction: column;
            }
            .sync-connector {
                transform: rotate(90deg);
            }
            .section-title {
                font-size: 1.6rem;
            }
            .creative-downloads {
                padding: 32px 20px;
            }
        }