<style>
        :root {
            --primary: #1a56db;
            --primary-light: #3b82f6;
            --secondary: #0f172a;
            --accent: #f97316;
            --bg: #f8fafc;
            --card-bg: #ffffff;
            --text: #1e293b;
            --text-light: #64748b;
            --border: #e2e8f0;
            --shadow: 0 4px 24px rgba(0,0,0,0.06);
            --radius: 16px;
            --transition: 0.25s ease;
        }
        * { margin:0; padding:0; box-sizing:border-box; }
        body {
            font-family: system-ui, -apple-system, 'Segoe UI', Roboto, 'Helvetica Neue', sans-serif;
            background: linear-gradient(135deg, #f0f4ff 0%, #ffffff 100%);
            color: var(--text);
            line-height: 1.6;
        }
        .container { max-width: 1200px; margin: 0 auto; padding: 0 20px; }
        header {
            background: rgba(255,255,255,0.85);
            backdrop-filter: blur(12px);
            position: sticky;
            top: 0;
            z-index: 100;
            border-bottom: 1px solid rgba(0,0,0,0.05);
        }
        .nav-bar {
            display: flex;
            justify-content: space-between;
            align-items: center;
            padding: 16px 0;
        }
        .logo {
            font-size: 1.8rem;
            font-weight: 700;
            color: var(--primary);
            text-decoration: none;
            display: flex;
            align-items: center;
            gap: 8px;
        }
        .logo span { background: var(--primary); color:#fff; padding:4px 12px; border-radius: 8px; font-size:1rem; }
        nav ul { display: flex; gap: 32px; list-style: none; }
        nav ul li a {
            text-decoration: none;
            font-weight: 500;
            color: var(--secondary);
            transition: color var(--transition);
            font-size: 1rem;
        }
        nav ul li a:hover { color: var(--primary); }
        .btn {
            display: inline-block;
            padding: 12px 28px;
            border-radius: 50px;
            font-weight: 600;
            text-decoration: none;
            transition: all var(--transition);
            cursor: pointer;
            border: none;
            font-size: 1rem;
        }
        .btn-primary { background: var(--primary); color: #fff; box-shadow: 0 4px 14px rgba(26,86,219,0.4); }
        .btn-primary:hover { background: var(--primary-light); transform: translateY(-2px); box-shadow: 0 6px 20px rgba(26,86,219,0.5); }
        .btn-outline { background: transparent; color: var(--primary); border: 2px solid var(--primary); }
        .btn-outline:hover { background: var(--primary); color: #fff; }
        .btn-accent { background: var(--accent); color: #fff; box-shadow: 0 4px 14px rgba(249,115,22,0.4); }
        .btn-accent:hover { background: #ea580c; }
        section { padding: 100px 0; }
        .section-title {
            font-size: 2.2rem;
            font-weight: 700;
            text-align: center;
            margin-bottom: 16px;
            color: var(--secondary);
        }
        .section-subtitle {
            text-align: center;
            color: var(--text-light);
            margin-bottom: 56px;
            font-size: 1.1rem;
        }
        .hero {
            padding: 100px 0 80px;
            text-align: center;
            position: relative;
        }
        .hero h1 {
            font-size: 3.2rem;
            font-weight: 800;
            background: linear-gradient(135deg, #1a56db, #7c3aed);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            margin-bottom: 24px;
        }
        .hero p {
            font-size: 1.25rem;
            color: var(--text-light);
            max-width: 640px;
            margin: 0 auto 36px;
        }
        .hero-btns { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }
        .card-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
            gap: 32px;
        }
        .card {
            background: var(--card-bg);
            border-radius: var(--radius);
            padding: 32px 24px;
            box-shadow: var(--shadow);
            transition: transform var(--transition), box-shadow var(--transition);
            text-align: center;
        }
        .card:hover { transform: translateY(-6px); box-shadow: 0 12px 32px rgba(0,0,0,0.1); }
        .card-icon {
            font-size: 2.5rem;
            margin-bottom: 16px;
            background: #eff6ff;
            width: 70px;
            height: 70px;
            display: flex;
            align-items: center;
            justify-content: center;
            border-radius: 20px;
            margin-left: auto;
            margin-right: auto;
        }
        .card h3 { font-size: 1.3rem; margin-bottom: 12px; font-weight: 600; }
        .card p { color: var(--text-light); font-size: 0.95rem; }
        .feature-row {
            display: flex;
            align-items: center;
            gap: 60px;
            margin-bottom: 60px;
            flex-wrap: wrap;
        }
        .feature-row.reverse { flex-direction: row-reverse; }
        .feature-text { flex: 1; min-width: 280px; }
        .feature-text h3 { font-size: 1.8rem; margin-bottom: 16px; }
        .feature-text p { color: var(--text-light); margin-bottom: 12px; }
        .feature-image {
            flex: 1;
            min-width: 280px;
            background: linear-gradient(145deg, #eef2ff, #ffffff);
            border-radius: var(--radius);
            height: 240px;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 3rem;
            color: var(--primary-light);
            box-shadow: var(--shadow);
        }
        .stats {
            display: flex;
            justify-content: space-around;
            flex-wrap: wrap;
            gap: 40px;
            text-align: center;
        }
        .stat-item .stat-number {
            font-size: 3rem;
            font-weight: 800;
            color: var(--primary);
        }
        .stat-label { color: var(--text-light); font-size: 1rem; }
        .testimonial-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
            gap: 32px;
        }
        .testimonial-card {
            background: var(--card-bg);
            border-radius: var(--radius);
            padding: 28px;
            box-shadow: var(--shadow);
        }
        .testimonial-card .user {
            display: flex;
            align-items: center;
            gap: 12px;
            margin-top: 16px;
        }
        .user-avatar {
            width: 44px; height: 44px;
            background: #cbd5e1;
            border-radius: 50%;
            font-weight: bold;
            display: flex;
            align-items: center;
            justify-content: center;
            color: #fff;
            background: var(--primary-light);
        }
        .stars { color: #fbbf24; margin-bottom: 8px; }
        .quote { font-style: italic; color: var(--text); }

        .node-map {
            display: flex;
            justify-content: center;
            gap: 40px;
            flex-wrap: wrap;
            background: #fff;
            border-radius: var(--radius);
            padding: 48px;
            box-shadow: var(--shadow);
        }
        .node-stat {
            text-align: center;
            min-width: 120px;
        }
        .node-stat .number {
            font-size: 2.8rem;
            font-weight: 800;
            color: var(--primary);
        }

        .pricing-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
            gap: 32px;
            align-items: stretch;
        }
        .pricing-card {
            background: white;
            border-radius: var(--radius);
            padding: 36px 24px;
            box-shadow: var(--shadow);
            text-align: center;
            display: flex;
            flex-direction: column;
        }
        .pricing-card.featured { border: 2px solid var(--primary); position: relative; }
        .pricing-card h3 { font-size: 1.5rem; margin-bottom: 12px; }
        .price { font-size: 2.5rem; font-weight: 800; color: var(--primary); margin: 16px 0; }
        .price small { font-size: 1rem; font-weight: 500; color: var(--text-light); }
        .features-list { list-style: none; margin: 24px 0; flex: 1; }
        .features-list li { padding: 8px 0; color: var(--text-light); }
        .safe-badge {
            display: flex;
            align-items: center;
            gap: 24px;
            background: #f0fdf4;
            border-radius: var(--radius);
            padding: 32px;
            box-shadow: var(--shadow);
            margin: 40px 0 0;
        }
        .safe-icon { font-size: 2.8rem; }
        .download-cards {
            display: flex;
            gap: 24px;
            justify-content: center;
            flex-wrap: wrap;
        }
        .dl-card {
            background: white;
            border-radius: var(--radius);
            padding: 32px 24px;
            box-shadow: var(--shadow);
            width: 200px;
            text-align: center;
        }
        .dl-card .platform-icon { font-size: 2.5rem; margin-bottom: 12px; }
        .dl-card h4 { margin-bottom: 8px; }
        .dl-card .btn { margin-top: 12px; }
        .faq-preview-list {
            max-width: 700px;
            margin: 0 auto;
        }
        .faq-item {
            background: white;
            border-radius: 12px;
            padding: 20px 28px;
            margin-bottom: 12px;
            box-shadow: 0 2px 8px rgba(0,0,0,0.04);
            cursor: pointer;
            transition: background var(--transition);
        }
        .faq-item:hover { background: #f1f5f9; }
        .faq-item h4 { margin-bottom: 6px; }
        /* 底部优化：更丰富的布局与层次 */
        footer {
            background: linear-gradient(180deg, #111827 0%, #0f172a 100%);
            color: #cbd5e1;
            padding: 64px 0 20px;
            margin-top: 100px;
            border-top: 1px solid #334155;
        }
        .footer-grid {
            display: flex;
            justify-content: space-between;
            flex-wrap: wrap;
            gap: 48px;
            margin-bottom: 40px;
        }
        .footer-brand {
            max-width: 260px;
        }
        .footer-logo {
            font-size: 1.8rem;
            font-weight: 700;
            color: #fff;
            margin-bottom: 12px;
            display: flex;
            align-items: center;
            gap: 6px;
        }
        .footer-desc {
            color: #94a3b8;
            font-size: 0.95rem;
            line-height: 1.6;
            margin-bottom: 20px;
        }
        .social-icons {
            display: flex;
            gap: 16px;
            font-size: 1.5rem;
        }
        .social-icons a {
            color: #94a3b8;
            text-decoration: none;
            transition: color var(--transition);
        }
        .social-icons a:hover { color: #fff; }
        .footer-links-group {
            display: flex;
            gap: 64px;
            flex-wrap: wrap;
        }
        .footer-col h4 {
            color: #fff;
            margin-bottom: 20px;
            font-size: 1rem;
            font-weight: 600;
        }
        .footer-col ul {
            list-style: none;
            display: flex;
            flex-direction: column;
            gap: 12px;
        }
        .footer-col ul li a {
            color: #94a3b8;
            text-decoration: none;
            font-size: 0.9rem;
            transition: color var(--transition);
        }
        .footer-col ul li a:hover { color: #fff; }
        .copyright-bar {
            border-top: 1px solid #1e293b;
            padding-top: 24px;
            text-align: center;
            font-size: 0.85rem;
            color: #64748b;
            display: flex;
            justify-content: space-between;
            align-items: center;
            flex-wrap: wrap;
            gap: 12px;
        }
        .copyright-bar a { color: #64748b; text-decoration: none; }
        .copyright-bar a:hover { color: #94a3b8; }
        @media (max-width: 768px) {
            .nav-bar { flex-direction: column; gap: 12px; }
            .hero h1 { font-size: 2.4rem; }
            .feature-row { flex-direction: column; }
            .footer-grid { flex-direction: column; gap: 32px; }
            .footer-links-group { gap: 32px; }
        }
    </style>