:root {
        --bg-primary: #0a0612;
        --bg-secondary: #0f0a1a;
        --bg-card: rgba(255, 255, 255, 0.03);
        --bg-card-hover: rgba(255, 255, 255, 0.06);
        --border-subtle: rgba(255, 255, 255, 0.08);
        --border-hover: rgba(168, 85, 247, 0.35);
        --text-primary: #f1f5f9;
        --text-secondary: #94a3b8;
        --text-muted: #64748b;
        --accent-purple: #a855f7;
        --accent-blue: #3b82f6;
        --accent-cyan: #06b6d4;
        --accent-green: #34d399;
        --accent-glow-purple: rgba(168, 85, 247, 0.15);
        --accent-glow-blue: rgba(59, 130, 246, 0.12);
        --accent-glow-cyan: rgba(6, 182, 212, 0.1);
        --gradient-hero: linear-gradient(120deg, #a855f7 0%, #7c3aed 30%, #3b82f6 65%, #06b6d4 100%);
        --gradient-quantum: linear-gradient(135deg, rgba(168, 85, 247, 0.4), rgba(6, 182, 212, 0.3));
        --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
    }

    * { margin: 0; padding: 0; box-sizing: border-box; }
    html { scroll-behavior: smooth; }
    body {
        font-family: var(--font-sans);
        background-color: var(--bg-primary);
        color: var(--text-primary);
        line-height: 1.7;
        overflow-x: hidden;
        -webkit-font-smoothing: antialiased;
    }
    a { color: inherit; text-decoration: none; transition: color 0.3s ease; }

    /* 量子背景 */
    .quantum-bg {
        position: fixed;
        top: 0; left: 0;
        width: 100vw; height: 100vh;
        pointer-events: none;
        z-index: 0;
        overflow: hidden;
    }
    .quantum-bg::before,
    .quantum-bg::after {
        content: '';
        position: absolute;
        border-radius: 50%;
        filter: blur(80px);
        opacity: 0.3;
        animation: quantumFloat 12s ease-in-out infinite alternate;
    }
    .quantum-bg::before {
        width: 500px; height: 500px;
        background: radial-gradient(circle, rgba(168, 85, 247, 0.25), transparent 70%);
        top: -100px; left: -100px;
    }
    .quantum-bg::after {
        width: 600px; height: 600px;
        background: radial-gradient(circle, rgba(6, 182, 212, 0.2), transparent 70%);
        bottom: -150px; right: -150px;
        animation-delay: -6s;
    }
    @keyframes quantumFloat {
        0% { transform: translate(0, 0) scale(1); }
        33% { transform: translate(40px, -30px) scale(1.15); }
        66% { transform: translate(-30px, 20px) scale(0.95); }
        100% { transform: translate(20px, -10px) scale(1.05); }
    }

    /* 头部导航 */
    header {
        position: fixed;
        top: 16px;
        left: 50%;
        transform: translateX(-50%);
        width: 94%;
        max-width: 1250px;
        background: rgba(10, 6, 18, 0.75);
        backdrop-filter: blur(24px);
        -webkit-backdrop-filter: blur(24px);
        border: 1px solid rgba(255, 255, 255, 0.1);
        border-radius: 50px;
        padding: 10px 24px;
        display: flex;
        justify-content: space-between;
        align-items: center;
        z-index: 1000;
        transition: all 0.3s ease;
    }
    header.scrolled {
        background: rgba(10, 6, 18, 0.92);
        box-shadow: 0 8px 40px rgba(0, 0, 0, 0.5);
    }
    .logo {
        display: flex;
        align-items: center;
        gap: 10px;
        font-size: 20px;
        font-weight: 800;
        flex-shrink: 0;
    }
    .logo-icon {
        width: 36px; height: 36px;
        background: var(--gradient-hero);
        border-radius: 10px;
        display: flex; align-items: center; justify-content: center;
        font-size: 15px; font-weight: 900; color: #fff;
        box-shadow: 0 0 24px rgba(168, 85, 247, 0.5);
        animation: logoGlow 3s ease-in-out infinite alternate;
    }
    @keyframes logoGlow {
        0% { box-shadow: 0 0 16px rgba(168, 85, 247, 0.4); }
        100% { box-shadow: 0 0 32px rgba(6, 182, 212, 0.5); }
    }
    .logo span {
        background: linear-gradient(90deg, #fff 60%, #a855f7);
        -webkit-background-clip: text;
        -webkit-text-fill-color: transparent;
        background-clip: text;
    }
    nav {
        flex: 1;
        display: flex;
        justify-content: center;
    }
    nav ul {
        display: flex;
        list-style: none;
        gap: 4px;
        font-size: 12.5px;
        color: var(--text-secondary);
        align-items: center;
        flex-wrap: nowrap;
    }
    nav ul li a {
        display: inline-block;
        padding: 6px 10px;
        border-radius: 20px;
        color: var(--text-secondary);
        font-weight: 500;
        transition: all 0.25s ease;
    }
    nav ul li a:hover { color: #fff; background: rgba(168, 85, 247, 0.12); }
    nav ul li a.active {
        color: #fff;
        background: rgba(168, 85, 247, 0.18);
        box-shadow: 0 0 12px rgba(168, 85, 247, 0.2);
    }
    nav ul li a::after {
        content: '';
        position: absolute;
        bottom: 0; left: 50%;
        transform: translateX(-50%);
        width: 0; height: 2px;
        background: var(--gradient-hero);
        border-radius: 2px;
        transition: width 0.3s ease;
    }
    nav ul li a:hover::after,
    nav ul li a.active::after { width: 60%; }
    .lang-select {
        font-size: 13px;
        color: var(--text-secondary);
        cursor: pointer;
        padding: 6px 12px;
        border: 1px solid rgba(255, 255, 255, 0.1);
        border-radius: 20px;
        transition: all 0.3s;
        flex-shrink: 0;
    }
    .lang-select:hover { border-color: rgba(168, 85, 247, 0.4); color: #fff; }

    main {
        position: relative;
        z-index: 1;
        max-width: 1200px;
        margin: 0 auto;
        padding: 170px 20px 60px;
    }

    /* 安全英雄区 */
    .security-hero {
        text-align: center;
        margin-bottom: 80px;
    }
    .hero-badge {
        display: inline-flex;
        align-items: center;
        gap: 8px;
        background: rgba(168, 85, 247, 0.1);
        border: 1px solid rgba(168, 85, 247, 0.3);
        border-radius: 50px;
        padding: 8px 18px;
        font-size: 12px;
        font-weight: 600;
        color: #c084fc;
        margin-bottom: 24px;
    }
    .pulse-dot {
        width: 7px; height: 7px;
        border-radius: 50%;
        background: #a855f7;
        animation: pulseDot 1.5s ease-in-out infinite;
    }
    @keyframes pulseDot {
        0%, 100% { box-shadow: 0 0 0 0 rgba(168,85,247,0.5); }
        50% { box-shadow: 0 0 0 8px rgba(168,85,247,0); }
    }
    .security-hero h1 {
        font-size: 52px;
        font-weight: 900;
        line-height: 1.2;
        letter-spacing: -1px;
        margin-bottom: 20px;
    }
    .gradient-text {
        background: var(--gradient-hero);
        -webkit-background-clip: text;
        -webkit-text-fill-color: transparent;
        background-clip: text;
    }
    .security-hero > p {
        font-size: 18px;
        color: var(--text-secondary);
        max-width: 760px;
        margin: 0 auto 30px;
        line-height: 1.8;
    }

    /* 双保险架构 */
    .dual-architecture {
        margin-bottom: 80px;
    }
    .section-header {
        display: flex;
        justify-content: space-between;
        align-items: flex-end;
        margin-bottom: 40px;
        flex-wrap: wrap;
        gap: 16px;
    }
    .section-tag {
        font-size: 12px;
        font-weight: 700;
        color: #06b6d4;
        letter-spacing: 2px;
        text-transform: uppercase;
        margin-bottom: 8px;
        display: block;
    }
    .section-title {
        font-size: 36px;
        font-weight: 800;
        line-height: 1.3;
        letter-spacing: -0.5px;
    }
    .section-title .accent { color: #a855f7; }
    .dual-grid {
        display: grid;
        grid-template-columns: repeat(2, 1fr);
        gap: 24px;
    }
    .dual-card {
        background: var(--bg-card);
        border: 1px solid var(--border-subtle);
        border-radius: 20px;
        padding: 32px 28px;
        position: relative;
        overflow: hidden;
        transition: all 0.4s;
    }
    .dual-card::before {
        content: '';
        position: absolute;
        top: 0; left: 0; right: 0;
        height: 2px;
        background: var(--gradient-hero);
        opacity: 0;
        transition: opacity 0.4s;
    }
    .dual-card:hover {
        border-color: var(--border-hover);
        transform: translateY(-4px);
        box-shadow: 0 16px 40px rgba(0,0,0,0.35);
    }
    .dual-card:hover::before { opacity: 1; }
    .card-icon {
        font-size: 42px;
        margin-bottom: 18px;
    }
    .dual-card h3 {
        font-size: 22px;
        font-weight: 700;
        margin-bottom: 12px;
    }
    .dual-card p {
        font-size: 14px;
        color: var(--text-secondary);
        line-height: 1.7;
    }
    .dual-card .highlight {
        color: #c084fc;
        font-weight: 600;
    }

    /* 端到端加密流程 */
    .e2ee-flow {
        margin-bottom: 80px;
        background: linear-gradient(135deg, rgba(6,182,212,0.04), rgba(168,85,247,0.04));
        border: 1px solid rgba(6,182,212,0.15);
        border-radius: 24px;
        padding: 48px 40px;
    }
    .flow-steps {
        display: grid;
        grid-template-columns: repeat(4, 1fr);
        gap: 20px;
        margin-top: 30px;
    }
    .flow-step {
        text-align: center;
        padding: 20px;
        background: rgba(255,255,255,0.02);
        border-radius: 16px;
    }
    .flow-step .step-icon {
        font-size: 28px;
        margin-bottom: 10px;
    }
    .flow-step h4 {
        font-size: 15px;
        font-weight: 700;
        margin-bottom: 8px;
    }
    .flow-step p {
        font-size: 12px;
        color: var(--text-secondary);
        line-height: 1.6;
    }

    /* 密钥本地管理 */
    .key-local {
        margin-bottom: 80px;
    }
    .local-grid {
        display: grid;
        grid-template-columns: repeat(3, 1fr);
        gap: 22px;
    }
    .local-item {
        background: var(--bg-card);
        border: 1px solid var(--border-subtle);
        border-radius: 16px;
        padding: 24px;
        transition: all 0.3s;
    }
    .local-item:hover {
        border-color: var(--border-hover);
        transform: translateY(-3px);
    }
    .local-icon {
        font-size: 32px;
        margin-bottom: 12px;
    }
    .local-item h4 {
        font-size: 17px;
        font-weight: 700;
        margin-bottom: 8px;
    }
    .local-item p {
        font-size: 13px;
        color: var(--text-secondary);
        line-height: 1.7;
    }

    /* 审计与渗透测试 */
    .audit-section {
        margin-bottom: 80px;
    }
    .audit-grid {
        display: grid;
        grid-template-columns: repeat(2, 1fr);
        gap: 22px;
    }
    .audit-card {
        background: var(--bg-card);
        border: 1px solid var(--border-subtle);
        border-radius: 18px;
        padding: 28px;
        transition: all 0.3s;
    }
    .audit-card:hover { border-color: var(--border-hover); }
    .audit-card h3 {
        font-size: 18px;
        font-weight: 700;
        margin-bottom: 10px;
        display: flex;
        align-items: center;
        gap: 10px;
    }
    .audit-card p {
        font-size: 13px;
        color: var(--text-secondary);
        line-height: 1.7;
    }
    .audit-badge {
        background: rgba(52, 211, 153, 0.15);
        color: #34d399;
        font-size: 10px;
        font-weight: 700;
        padding: 2px 10px;
        border-radius: 12px;
        margin-left: 8px;
    }

    /* 威胁防御统计 */
    .threat-stats {
        margin-bottom: 80px;
        display: grid;
        grid-template-columns: repeat(4, 1fr);
        gap: 18px;
    }
    .threat-stat {
        background: var(--bg-card);
        border: 1px solid var(--border-subtle);
        border-radius: 16px;
        padding: 24px 18px;
        text-align: center;
        transition: all 0.3s;
    }
    .threat-stat:hover { border-color: var(--border-hover); }
    .threat-stat .value {
        font-size: 32px;
        font-weight: 900;
        background: var(--gradient-hero);
        -webkit-background-clip: text;
        -webkit-text-fill-color: transparent;
        background-clip: text;
    }
    .threat-stat .label {
        font-size: 12px;
        color: var(--text-secondary);
        margin-top: 8px;
    }

    /* 安全认证标志 */
    .cert-section {
        margin-bottom: 80px;
        text-align: center;
    }
    .cert-logos {
        display: flex;
        flex-wrap: wrap;
        justify-content: center;
        gap: 30px;
        margin-top: 30px;
    }
    .cert-logo {
        background: rgba(255,255,255,0.03);
        border: 1px solid var(--border-subtle);
        border-radius: 14px;
        padding: 18px 24px;
        font-size: 14px;
        font-weight: 600;
        color: #cbd5e1;
        display: flex;
        align-items: center;
        gap: 8px;
        transition: all 0.3s;
    }
    .cert-logo:hover { border-color: var(--border-hover); }

    /* FAQ */
    .faq-section {
        margin-bottom: 80px;
    }
    .faq-item {
        background: var(--bg-card);
        border: 1px solid var(--border-subtle);
        border-radius: 12px;
        margin-bottom: 12px;
        overflow: hidden;
    }
    .faq-question {
        padding: 18px 20px;
        font-weight: 600;
        cursor: pointer;
        display: flex;
        justify-content: space-between;
        align-items: center;
        transition: background 0.3s;
    }
    .faq-question:hover { background: rgba(255,255,255,0.03); }
    .faq-question .icon { font-size: 20px; color: #a855f7; }
    .faq-answer {
        padding: 0 20px 18px;
        font-size: 14px;
        color: var(--text-secondary);
        line-height: 1.7;
    }

    /* 下载报告 CTA */
    .report-cta {
        background: linear-gradient(135deg, rgba(168,85,247,0.08), rgba(6,182,212,0.06));
        border: 1px solid rgba(168,85,247,0.25);
        border-radius: 24px;
        padding: 40px 36px;
        text-align: center;
        margin-bottom: 60px;
    }
    .report-cta h3 {
        font-size: 26px;
        font-weight: 800;
        margin-bottom: 12px;
    }
    .report-cta p {
        font-size: 15px;
        color: var(--text-secondary);
        margin-bottom: 24px;
    }
    .btn-primary {
        background: var(--gradient-hero);
        border-radius: 50px;
        padding: 14px 32px;
        font-size: 15px;
        font-weight: 700;
        color: #fff;
        box-shadow: 0 8px 30px rgba(168,85,247,0.4);
        transition: all 0.3s;
        display: inline-block;
    }
    .btn-primary:hover { transform: translateY(-2px); box-shadow: 0 14px 40px rgba(168,85,247,0.6); }

    /* 页脚 */
    footer {
        border-top: 1px solid var(--border-subtle);
        padding: 60px 20px 30px;
        background-color: var(--bg-primary);
        position: relative;
        z-index: 1;
    }
    .footer-container { max-width: 1200px; margin: 0 auto; }
    .footer-grid {
        display: grid;
        grid-template-columns: repeat(4, 1fr);
        gap: 40px;
        margin-bottom: 50px;
    }
    .footer-col h4 {
        font-size: 14px;
        font-weight: 700;
        color: var(--text-primary);
        margin-bottom: 18px;
    }
    .footer-col ul {
        list-style: none;
        display: flex;
        flex-direction: column;
        gap: 10px;
    }
    .footer-col ul li,
    .footer-col ul li a {
        font-size: 13px;
        color: var(--text-secondary);
        transition: color 0.25s;
    }
    .footer-col ul li a:hover { color: #c084fc; }
    .footer-bottom {
        text-align: center;
        font-size: 12px;
        color: var(--text-muted);
        padding-top: 24px;
        border-top: 1px solid var(--border-subtle);
    }
    .footer-bottom .footer-links {
        display: flex;
        justify-content: center;
        gap: 20px;
        font-size: 11px;
        margin-top: 6px;
    }
    .footer-bottom .footer-links a { color: var(--text-muted); }
    .footer-bottom .footer-links a:hover { color: #c084fc; }

    /* 响应式 */
    @media (max-width: 1100px) {
        header { width: 96%; padding: 10px 16px; }
        nav ul { gap: 2px; font-size: 11px; }
        nav ul li a { padding: 5px 7px; }
        .dual-grid, .local-grid, .audit-grid { grid-template-columns: 1fr 1fr; }
        .flow-steps { grid-template-columns: 1fr 1fr; }
        .threat-stats { grid-template-columns: repeat(2, 1fr); }
    }
    @media (max-width: 768px) {
        main { padding-top: 130px; }
        .security-hero h1 { font-size: 34px; }
        .dual-grid, .local-grid, .audit-grid, .flow-steps { grid-template-columns: 1fr; }
        .threat-stats { grid-template-columns: 1fr 1fr; }
        .footer-grid { grid-template-columns: 1fr 1fr; gap: 24px; }
        .section-title { font-size: 28px; }
    }