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

        :root {
            --brand: #e85d3a;
            --brand-deep: #c94a2c;
            --brand-glow: #f7931e;
            --bg-warm: #fdfaf7;
            --bg-cream: #fcf8f3;
            --bg-soft: #f5ede4;
            --text-primary: #1e1a16;
            --text-secondary: rgba(30, 26, 22, 0.58);
            --text-muted: rgba(30, 26, 22, 0.38);
            --border-soft: rgba(0, 0, 0, 0.04);
            --border-card: rgba(0, 0, 0, 0.05);
            --shadow-card: 0 2px 14px rgba(0, 0, 0, 0.025);
            --shadow-hover: 0 22px 56px rgba(0, 0, 0, 0.06);
            --radius-lg: 24px;
            --radius-xl: 32px;
            --radius-full: 60px;
            --font-mono: 'SF Mono', 'Fira Code', 'Consolas', 'Monaco', monospace;
            --transition-smooth: 0.3s cubic-bezier(0.22, 0.61, 0.36, 1);
        }

        body {
            font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
            background: var(--bg-warm);
            color: var(--text-primary);
            line-height: 1.6;
            -webkit-font-smoothing: antialiased;
            overflow-x: hidden;
        }

        a {
            text-decoration: none;
            color: inherit;
        }

        .container {
            max-width: 1220px;
            margin: 0 auto;
            padding: 0 32px;
        }

        /* ── Header ───────────────────── */
        header {
            background: rgba(253, 250, 247, 0.9);
            backdrop-filter: blur(16px);
            -webkit-backdrop-filter: blur(16px);
            padding: 15px 0;
            position: sticky;
            top: 0;
            z-index: 100;
            border-bottom: 1px solid var(--border-soft);
            transition: box-shadow var(--transition-smooth);
        }
        header.scrolled {
            box-shadow: 0 1px 20px rgba(0, 0, 0, 0.04);
        }
        .header-inner {
            display: flex;
            align-items: center;
            justify-content: space-between;
            flex-wrap: wrap;
            gap: 12px;
        }
        .logo {
            font-size: 28px;
            font-weight: 800;
            letter-spacing: -0.5px;
            display: flex;
            align-items: center;
            gap: 10px;
            color: var(--text-primary);
            transition: opacity var(--transition-smooth);
        }
        .logo:hover {
            opacity: 0.8;
        }
        .logo svg {
            width: 34px;
            height: 34px;
            color: var(--brand);
            flex-shrink: 0;
        }
        .logo span {
            color: var(--brand);
        }
        .logo small {
            font-size: 13px;
            font-weight: 400;
            color: var(--text-muted);
            margin-left: 4px;
            letter-spacing: 0.3px;
        }
        nav {
            display: flex;
            align-items: center;
            gap: 30px;
            flex-wrap: wrap;
        }
        nav a {
            font-size: 14px;
            font-weight: 500;
            color: var(--text-secondary);
            transition: color 0.25s;
            position: relative;
            padding: 5px 0;
            border-bottom: 2px solid transparent;
            letter-spacing: 0.1px;
        }
        nav a:hover {
            color: var(--text-primary);
        }
        nav a.active {
            color: var(--brand);
            border-bottom-color: var(--brand);
        }
        .nav-download-btn {
            background: var(--brand);
            color: #fff !important;
            padding: 11px 32px;
            border-radius: var(--radius-full);
            font-weight: 600;
            font-size: 13px;
            border: none;
            transition: background var(--transition-smooth), transform 0.2s, box-shadow 0.3s;
            border-bottom: none !important;
            box-shadow: 0 5px 20px rgba(232, 93, 58, 0.22);
            letter-spacing: 0.2px;
        }
        .nav-download-btn:hover {
            background: var(--brand-deep);
            transform: scale(1.04);
            box-shadow: 0 8px 28px rgba(232, 93, 58, 0.32);
            color: #fff !important;
        }
        .nav-toggle {
            display: none;
            flex-direction: column;
            gap: 5px;
            cursor: pointer;
            background: none;
            border: none;
            padding: 8px;
            z-index: 101;
        }
        .nav-toggle span {
            display: block;
            width: 26px;
            height: 2px;
            background: var(--text-primary);
            border-radius: 2px;
            transition: 0.25s;
            transform-origin: center;
        }
        .nav-toggle.open span:nth-child(1) {
            transform: rotate(45deg) translate(5px, 5px);
        }
        .nav-toggle.open span:nth-child(2) {
            opacity: 0;
            transform: scaleX(0);
        }
        .nav-toggle.open span:nth-child(3) {
            transform: rotate(-45deg) translate(5px, -5px);
        }

        /* ── 架构页 Hero ───────────────── */
        .arch-hero {
            padding: 90px 0 70px;
            background: linear-gradient(160deg, #fdfaf7 0%, #f5ede4 100%);
            border-bottom: 1px solid var(--border-soft);
            position: relative;
            overflow: hidden;
        }
        .arch-hero::before {
            content: '';
            position: absolute;
            top: -20%;
            right: -5%;
            width: 700px;
            height: 700px;
            background: radial-gradient(circle, rgba(232, 93, 58, 0.05) 0%, transparent 70%);
            border-radius: 50%;
            pointer-events: none;
        }
        .arch-hero .container {
            position: relative;
            z-index: 2;
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 50px;
            align-items: center;
        }
        .arch-hero-content h1 {
            font-size: 48px;
            font-weight: 800;
            line-height: 1.1;
            letter-spacing: -1.2px;
            margin-bottom: 16px;
            color: var(--text-primary);
        }
        .arch-hero-content .highlight {
            background: linear-gradient(135deg, #e85d3a, #f7931e);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            background-clip: text;
        }
        .arch-hero-content .sub {
            font-size: 18px;
            color: var(--text-secondary);
            max-width: 480px;
            margin-bottom: 28px;
            line-height: 1.7;
        }
        .arch-hero-content .arch-badge-list {
            display: flex;
            flex-wrap: wrap;
            gap: 14px;
            margin-bottom: 30px;
        }
        .arch-hero-content .arch-badge {
            background: rgba(232, 93, 58, 0.08);
            color: var(--brand);
            font-size: 13px;
            font-weight: 600;
            padding: 6px 18px;
            border-radius: 40px;
            letter-spacing: 0.4px;
        }
        .arch-visual {
            display: flex;
            justify-content: center;
            align-items: center;
        }
        .arch-diagram {
            background: rgba(255,255,255,0.65);
            backdrop-filter: blur(8px);
            border-radius: 28px;
            padding: 28px 24px;
            border: 1px solid rgba(255,255,255,0.7);
            box-shadow: 0 25px 50px rgba(0,0,0,0.04);
            width: 100%;
            max-width: 460px;
        }
        .arch-diagram .flow {
            display: flex;
            flex-direction: column;
            gap: 14px;
        }
        .arch-diagram .flow-node {
            display: flex;
            align-items: center;
            gap: 14px;
            background: rgba(0,0,0,0.015);
            border-radius: 16px;
            padding: 12px 16px;
            border: 1px solid rgba(0,0,0,0.03);
            transition: all var(--transition-smooth);
        }
        .arch-diagram .flow-node:hover {
            background: rgba(232,93,58,0.03);
            border-color: rgba(232,93,58,0.12);
        }
        .flow-node .node-icon {
            font-size: 22px;
            width: 40px;
            height: 40px;
            display: flex;
            align-items: center;
            justify-content: center;
            background: rgba(232,93,58,0.06);
            border-radius: 12px;
            flex-shrink: 0;
        }
        .flow-node .node-text strong {
            display: block;
            font-size: 15px;
            font-weight: 600;
            color: var(--text-primary);
        }
        .flow-node .node-text span {
            font-size: 12px;
            color: var(--text-muted);
        }
        .arch-diagram .encrypted-tag {
            display: inline-block;
            background: var(--brand);
            color: #fff;
            font-size: 10px;
            font-weight: 700;
            padding: 2px 10px;
            border-radius: 20px;
            margin-left: 6px;
            letter-spacing: 0.5px;
        }

        /* ── 通用版块 ───────────────── */
        .section-label {
            font-size: 12px;
            font-weight: 600;
            text-transform: uppercase;
            letter-spacing: 2.8px;
            color: var(--brand);
            text-align: center;
            margin-bottom: 8px;
        }
        .section-title {
            text-align: center;
            font-size: 38px;
            font-weight: 700;
            letter-spacing: -0.6px;
            margin-bottom: 14px;
            color: var(--text-primary);
        }
        .section-sub {
            text-align: center;
            color: var(--text-secondary);
            max-width: 560px;
            margin: 0 auto 48px;
            font-size: 17px;
            line-height: 1.7;
        }

        /* ── 创意版块1：消息加密旅程 ── */
        .journey-section {
            padding: 80px 0 70px;
            background: var(--bg-cream);
            border-bottom: 1px solid var(--border-soft);
            position: relative;
        }
        .journey-grid {
            display: grid;
            grid-template-columns: repeat(4, 1fr);
            gap: 20px;
            position: relative;
            z-index: 2;
        }
        .journey-card {
            background: #fff;
            border-radius: var(--radius-lg);
            padding: 28px 20px 24px;
            text-align: center;
            border: 1px solid var(--border-card);
            box-shadow: var(--shadow-card);
            transition: transform var(--transition-smooth), box-shadow var(--transition-smooth);
            position: relative;
        }
        .journey-card:hover {
            transform: translateY(-6px);
            box-shadow: var(--shadow-hover);
        }
        .journey-card .step-num {
            display: inline-block;
            background: var(--brand);
            color: #fff;
            font-weight: 700;
            font-size: 14px;
            width: 36px;
            height: 36px;
            line-height: 36px;
            border-radius: 50%;
            margin-bottom: 12px;
        }
        .journey-card h3 {
            font-size: 18px;
            font-weight: 700;
            margin-bottom: 6px;
        }
        .journey-card p {
            font-size: 14px;
            color: var(--text-secondary);
            line-height: 1.6;
        }
        .journey-connector {
            display: none;
        }

        /* ── 创意版块2：安全支柱双列 ── */
        .pillars-section {
            padding: 80px 0 70px;
            background: var(--bg-warm);
            border-bottom: 1px solid var(--border-soft);
        }
        .pillars-grid {
            display: grid;
            grid-template-columns: repeat(2, 1fr);
            gap: 32px;
        }
        .pillar-card {
            background: #fff;
            border-radius: var(--radius-lg);
            padding: 36px 32px;
            border: 1px solid var(--border-card);
            box-shadow: var(--shadow-card);
            transition: all var(--transition-smooth);
            display: flex;
            gap: 20px;
        }
        .pillar-card:hover {
            transform: translateY(-5px);
            box-shadow: var(--shadow-hover);
            border-color: rgba(232,93,58,0.12);
        }
        .pillar-icon {
            font-size: 38px;
            width: 60px;
            flex-shrink: 0;
        }
        .pillar-text h3 {
            font-size: 21px;
            font-weight: 700;
            margin-bottom: 8px;
        }
        .pillar-text p {
            font-size: 15px;
            color: var(--text-secondary);
            line-height: 1.65;
        }

        /* ── 数据仪表盘 ── */
        .metrics-section {
            padding: 70px 0 80px;
            background: var(--bg-cream);
            border-bottom: 1px solid var(--border-soft);
        }
        .metrics-grid {
            display: grid;
            grid-template-columns: repeat(4, 1fr);
            gap: 22px;
        }
        .metric-card {
            background: #fff;
            border-radius: var(--radius-lg);
            padding: 24px 18px;
            text-align: center;
            border: 1px solid var(--border-card);
            box-shadow: var(--shadow-card);
            transition: transform var(--transition-smooth);
        }
        .metric-card:hover {
            transform: translateY(-4px);
        }
        .metric-value {
            font-size: 32px;
            font-weight: 700;
            color: var(--brand);
            font-family: var(--font-mono);
            letter-spacing: -0.5px;
        }
        .metric-label {
            font-size: 13px;
            color: var(--text-muted);
            margin-top: 4px;
        }

        /* ── 详细解释区 ── */
        .detail-section {
            padding: 80px 0 70px;
            background: var(--bg-warm);
            border-bottom: 1px solid var(--border-soft);
        }
        .detail-row {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 40px;
            align-items: center;
            margin-bottom: 48px;
        }
        .detail-row:last-child {
            margin-bottom: 0;
        }
        .detail-text h3 {
            font-size: 28px;
            font-weight: 700;
            margin-bottom: 12px;
            letter-spacing: -0.4px;
        }
        .detail-text p {
            font-size: 16px;
            color: var(--text-secondary);
            line-height: 1.7;
        }
        .detail-illustration {
            background: rgba(255,255,255,0.6);
            border-radius: 24px;
            padding: 24px;
            border: 1px solid rgba(0,0,0,0.04);
            display: flex;
            justify-content: center;
            align-items: center;
            min-height: 180px;
            font-size: 40px;
            color: var(--brand);
        }

        /* ── CTA ───────────────────── */
        .cta-section {
            padding: 80px 0 90px;
            background: linear-gradient(155deg, #fdfaf7, #f5ede4);
            text-align: center;
            border-top: 1px solid var(--border-soft);
        }
        .cta-section h2 {
            font-size: 36px;
            font-weight: 700;
            letter-spacing: -0.5px;
            margin-bottom: 12px;
        }
        .cta-section p {
            color: var(--text-secondary);
            font-size: 17px;
            max-width: 420px;
            margin: 0 auto 30px;
        }
        .btn-primary {
            background: linear-gradient(135deg, #e85d3a, #f0844e);
            color: #fff;
            padding: 16px 48px;
            border-radius: 60px;
            font-weight: 600;
            font-size: 15px;
            border: none;
            cursor: pointer;
            transition: transform 0.25s, box-shadow 0.3s;
            display: inline-flex;
            align-items: center;
            gap: 8px;
            box-shadow: 0 9px 34px rgba(232,93,58,0.22);
        }
        .btn-primary:hover {
            transform: translateY(-4px);
            box-shadow: 0 16px 48px rgba(232,93,58,0.32);
        }

        /* ── Footer ───────────────────── */
        footer {
            background: #1e1a16;
            color: rgba(255,255,255,0.35);
            padding: 50px 0 30px;
            border-top: 1px solid rgba(255,255,255,0.05);
        }
        .footer-inner {
            display: grid;
            grid-template-columns: 2fr 1fr 1fr 1fr;
            gap: 40px;
        }
        .footer-brand .logo {
            font-size: 22px;
            margin-bottom: 10px;
            color: #fff;
        }
        .footer-brand .logo svg {
            color: var(--brand);
        }
        .footer-brand .logo span {
            color: var(--brand);
        }
        .footer-brand p {
            font-size: 14px;
            max-width: 260px;
            color: rgba(255,255,255,0.35);
        }
        .footer-col h4 {
            color: rgba(255,255,255,0.7);
            font-size: 15px;
            margin-bottom: 14px;
            font-weight: 600;
        }
        .footer-col a {
            display: block;
            font-size: 14px;
            color: rgba(255,255,255,0.35);
            margin-bottom: 8px;
            transition: color 0.2s;
        }
        .footer-col a:hover {
            color: #fff;
        }
        .footer-bottom {
            border-top: 1px solid rgba(255,255,255,0.05);
            padding-top: 22px;
            margin-top: 32px;
            display: flex;
            justify-content: space-between;
            flex-wrap: wrap;
            font-size: 13px;
            color: rgba(255,255,255,0.2);
        }
        .footer-bottom .platforms-badge {
            display: flex;
            gap: 16px;
        }

        /* ── Responsive ────────────── */
        @media (max-width: 1024px) {
            .arch-hero .container {
                grid-template-columns: 1fr;
                text-align: center;
            }
            .arch-hero-content .sub {
                margin: 0 auto 28px;
            }
            .arch-hero-content .arch-badge-list {
                justify-content: center;
            }
            .arch-diagram {
                max-width: 400px;
                margin: 0 auto;
            }
            .journey-grid {
                grid-template-columns: repeat(2, 1fr);
            }
            .pillars-grid {
                grid-template-columns: 1fr;
                max-width: 600px;
                margin: 0 auto;
            }
            .metrics-grid {
                grid-template-columns: repeat(2, 1fr);
            }
            .detail-row {
                grid-template-columns: 1fr;
                text-align: center;
            }
            .detail-illustration {
                min-height: 140px;
            }
        }
        @media (max-width: 768px) {
            nav {
                display: none;
                width: 100%;
                flex-direction: column;
                align-items: flex-start;
                gap: 14px;
                padding: 16px 0 8px;
                border-top: 1px solid var(--border-soft);
                margin-top: 12px;
            }
            nav.open {
                display: flex;
            }
            .nav-toggle {
                display: flex;
            }
            .arch-hero-content h1 {
                font-size: 36px;
            }
            .journey-grid {
                grid-template-columns: 1fr;
                max-width: 360px;
                margin: 0 auto;
            }
            .metrics-grid {
                grid-template-columns: 1fr 1fr;
                gap: 14px;
            }
            .section-title {
                font-size: 30px;
            }
            .footer-inner {
                grid-template-columns: 1fr 1fr;
                gap: 24px;
            }
        }
        @media (max-width: 480px) {
            .container {
                padding: 0 18px;
            }
            .arch-hero-content h1 {
                font-size: 28px;
            }
            .pillar-card {
                flex-direction: column;
                text-align: center;
            }
            .pillar-icon {
                margin: 0 auto;
            }
            .footer-inner {
                grid-template-columns: 1fr;
            }
        }