:root {
            --bg-deep: #060b14;
            --bg-card: rgba(14, 22, 40, 0.75);
            --bg-elevated: rgba(20, 32, 56, 0.8);
            --accent-sky: #38bdf8;
            --accent-glow: rgba(56, 189, 248, 0.28);
            --accent-purple: #a78bfa;
            --text-primary: #edf2f9;
            --text-secondary: #b0bec5;
            --text-tertiary: #6b7c93;
            --border-subtle: rgba(255, 255, 255, 0.07);
            --border-active: rgba(56, 189, 248, 0.45);
            --radius-sm: 10px;
            --radius-md: 16px;
            --radius-lg: 22px;
            --shadow-card: 0 8px 28px rgba(0, 0, 0, 0.35);
            --shadow-glow-sky: 0 0 40px rgba(56, 189, 248, 0.18);
            --transition-smooth: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
        }

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

        html {
            scroll-behavior: smooth;
            -webkit-font-smoothing: antialiased;
        }

        body {
            font-family: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
            color: var(--text-primary);
            background-color: var(--bg-deep);
            line-height: 1.65;
            overflow-x: hidden;
            letter-spacing: 0.01em;
        }

        .ambient-glow-layer {
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            pointer-events: none;
            z-index: 0;
            overflow: hidden;
        }
        .ambient-orb {
            position: absolute;
            border-radius: 50%;
            filter: blur(130px);
            opacity: 0.12;
            animation: orbDrift 20s ease-in-out infinite;
        }
        .ambient-orb.orb-sky {
            width: 650px;
            height: 650px;
            background: radial-gradient(circle, rgba(56, 189, 248, 0.6) 0%, transparent 70%);
            top: -200px;
            right: -160px;
        }
        .ambient-orb.orb-purple {
            width: 500px;
            height: 500px;
            background: radial-gradient(circle, rgba(167, 139, 250, 0.5) 0%, transparent 70%);
            bottom: -180px;
            left: -140px;
            animation-delay: -8s;
        }
        @keyframes orbDrift {
            0%, 100% { transform: translate(0, 0) scale(1); }
            25% { transform: translate(50px, -30px) scale(1.07); }
            50% { transform: translate(-40px, 40px) scale(0.94); }
            75% { transform: translate(-35px, -20px) scale(1.04); }
        }
        .grid-texture {
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            pointer-events: none;
            z-index: 0;
            opacity: 0.025;
            background-image:
                linear-gradient(rgba(255,255,255,0.05) 1px, transparent 1px),
                linear-gradient(90deg, rgba(255,255,255,0.05) 1px, transparent 1px);
            background-size: 54px 54px;
        }

        header {
            background: rgba(6, 11, 20, 0.82);
            backdrop-filter: blur(18px);
            -webkit-backdrop-filter: blur(18px);
            border-bottom: 1px solid var(--border-subtle);
            position: sticky;
            top: 0;
            z-index: 100;
            transition: background 0.35s;
        }
        .nav-container {
            max-width: 1260px;
            margin: 0 auto;
            padding: 1.1rem 2rem;
            display: flex;
            justify-content: space-between;
            align-items: center;
            gap: 1.5rem;
        }
        .logo {
            font-size: 1.55rem;
            font-weight: 800;
            color: #fff;
            text-decoration: none;
            display: flex;
            align-items: center;
            gap: 0.7rem;
            letter-spacing: -0.4px;
            white-space: nowrap;
        }
        .logo svg {
            width: 34px;
            height: 34px;
            fill: none;
            stroke: var(--accent-sky);
            stroke-width: 2;
            stroke-linecap: round;
            stroke-linejoin: round;
            filter: drop-shadow(0 0 10px var(--accent-glow));
        }
        .nav-links {
            display: flex;
            gap: 2.2rem;
            list-style: none;
            align-items: center;
        }
        .nav-links a {
            text-decoration: none;
            color: var(--text-secondary);
            font-weight: 540;
            font-size: 0.93rem;
            transition: all 0.25s;
            position: relative;
            padding: 0.35rem 0;
            white-space: nowrap;
        }
        .nav-links a::after {
            content: '';
            position: absolute;
            bottom: -2px;
            left: 0;
            width: 0;
            height: 2px;
            background: var(--accent-sky);
            border-radius: 2px;
            transition: width 0.28s ease;
        }
        .nav-links a:hover,
        .nav-links a.active {
            color: #ffffff;
        }
        .nav-links a:hover::after,
        .nav-links a.active::after {
            width: 100%;
        }
        .nav-links a.active {
            color: var(--accent-sky);
        }

        .nav-toggle {
            display: none;
            background: none;
            border: none;
            cursor: pointer;
            padding: 0.5rem;
            z-index: 101;
        }
        .nav-toggle span {
            display: block;
            width: 26px;
            height: 2.5px;
            background: var(--text-primary);
            margin: 6px 0;
            border-radius: 2px;
            transition: 0.3s;
        }

        @media (max-width: 860px) {
            .nav-links {
                display: none;
                position: absolute;
                top: 100%;
                left: 0;
                right: 0;
                background: rgba(6, 11, 20, 0.96);
                backdrop-filter: blur(20px);
                flex-direction: column;
                gap: 0;
                padding: 1rem 0;
                border-bottom: 1px solid var(--border-subtle);
                box-shadow: 0 12px 32px rgba(0,0,0,0.5);
            }
            .nav-links.open {
                display: flex;
            }
            .nav-links a {
                padding: 1rem 2rem;
                width: 100%;
                border-bottom: 1px solid rgba(255,255,255,0.04);
            }
            .nav-links a::after { display: none; }
            .nav-toggle { display: block; }
        }

        .hero {
            position: relative;
            padding: 5.5rem 2rem 3.5rem 2rem;
            text-align: center;
            z-index: 1;
        }
        .hero-container {
            max-width: 800px;
            margin: 0 auto;
        }
        .hero h1 {
            font-size: 2.9rem;
            font-weight: 850;
            margin-bottom: 1.2rem;
            line-height: 1.18;
            background: linear-gradient(140deg, #ffffff 0%, #cbd5e1 45%, #94a3b8 100%);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            background-clip: text;
            letter-spacing: -0.6px;
        }
        .hero p {
            font-size: 1.15rem;
            color: var(--text-secondary);
            max-width: 620px;
            margin: 0 auto 2.2rem auto;
            line-height: 1.65;
        }
        .hero .trust-line {
            display: flex;
            justify-content: center;
            gap: 2rem;
            flex-wrap: wrap;
            color: var(--text-tertiary);
            font-size: 0.85rem;
        }
        .hero .trust-line span {
            display: flex;
            align-items: center;
            gap: 0.4rem;
        }
        .hero .trust-line svg {
            width: 16px;
            height: 16px;
            stroke: var(--accent-sky);
            fill: none;
            stroke-width: 2;
        }

        .section-container {
            max-width: 1200px;
            margin: 0 auto;
            padding: 4.5rem 2rem;
            position: relative;
            z-index: 1;
        }
        .section-header {
            text-align: center;
            margin-bottom: 3.5rem;
        }
        .section-subtitle {
            color: var(--accent-sky);
            font-size: 0.8rem;
            font-weight: 700;
            text-transform: uppercase;
            letter-spacing: 1.8px;
            margin-bottom: 0.5rem;
            display: block;
        }
        .section-title {
            font-size: 2.1rem;
            font-weight: 750;
            color: #ffffff;
            letter-spacing: -0.3px;
        }
        .section-desc {
            color: var(--text-secondary);
            font-size: 0.98rem;
            margin-top: 0.7rem;
            max-width: 600px;
            margin-left: auto;
            margin-right: auto;
        }

        .download-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
            gap: 1.6rem;
            margin-bottom: 4rem;
        }
        .download-card {
            background: var(--bg-card);
            border: 1px solid var(--border-subtle);
            border-radius: 20px;
            padding: 2.2rem 1.8rem;
            text-align: center;
            transition: all var(--transition-smooth);
            backdrop-filter: blur(10px);
            display: flex;
            flex-direction: column;
            justify-content: space-between;
            position: relative;
        }
        .download-card.featured {
            border-color: rgba(56, 189, 248, 0.3);
            box-shadow: 0 0 24px rgba(56,189,248,0.12);
        }
        .download-card:hover {
            background: var(--bg-elevated);
            border-color: var(--border-active);
            transform: translateY(-6px);
            box-shadow: var(--shadow-card), var(--shadow-glow-sky);
        }
        .platform-badge {
            position: absolute;
            top: 1rem;
            right: 1rem;
            font-size: 0.72rem;
            padding: 0.2rem 0.7rem;
            border-radius: 9999px;
            background: rgba(56,189,248,0.12);
            color: var(--accent-sky);
            font-weight: 650;
            letter-spacing: 0.3px;
        }
        .platform-icon {
            width: 62px;
            height: 62px;
            border-radius: 16px;
            background: rgba(255,255,255,0.03);
            border: 1px solid var(--border-subtle);
            display: flex;
            align-items: center;
            justify-content: center;
            margin: 0 auto 1.3rem auto;
            transition: border-color 0.3s;
        }
        .download-card:hover .platform-icon {
            border-color: var(--border-active);
        }
        .platform-icon svg {
            width: 32px;
            height: 32px;
            fill: currentColor;
            color: var(--text-primary);
            transition: color 0.3s;
        }
        .download-card:hover .platform-icon svg {
            color: var(--accent-sky);
        }
        .download-card h2 {
            font-size: 1.45rem;
            color: #fff;
            margin-bottom: 0.4rem;
            font-weight: 700;
        }
        .version-info {
            font-size: 0.85rem;
            color: var(--text-secondary);
            margin-bottom: 0.9rem;
        }
        .signature-badge {
            font-size: 0.78rem;
            color: #34d399;
            background: rgba(52,211,153,0.08);
            padding: 0.3rem 0.8rem;
            border-radius: 9999px;
            display: inline-block;
            margin-bottom: 1.2rem;
            border: 1px solid rgba(52,211,153,0.25);
            letter-spacing: 0.2px;
        }
        .meta-list {
            list-style: none;
            margin-bottom: 1.8rem;
            font-size: 0.84rem;
            color: var(--text-tertiary);
            text-align: left;
            border-top: 1px solid var(--border-subtle);
            padding-top: 1rem;
        }
        .meta-list li {
            display: flex;
            justify-content: space-between;
            margin-bottom: 0.45rem;
        }
        .card-actions {
            display: flex;
            flex-direction: column;
            gap: 0.7rem;
        }
        .btn {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            gap: 0.6rem;
            height: 48px;
            padding: 0 1.5rem;
            font-size: 0.94rem;
            font-weight: 620;
            border-radius: var(--radius-sm);
            text-decoration: none;
            transition: all var(--transition-smooth);
            width: 100%;
            letter-spacing: 0.2px;
        }
        .btn-primary {
            background: linear-gradient(135deg, var(--accent-sky) 0%, #0284c7 100%);
            color: #041018;
            box-shadow: 0 0 22px var(--accent-glow);
        }
        .btn-primary:hover {
            transform: translateY(-3px);
            box-shadow: 0 0 38px rgba(56,189,248,0.45);
        }
        .btn-secondary {
            background: rgba(255,255,255,0.04);
            color: #ffffff;
            border: 1px solid var(--border-subtle);
        }
        .btn-secondary:hover {
            background: rgba(255,255,255,0.1);
            border-color: rgba(255,255,255,0.22);
            transform: translateY(-3px);
        }

        /* 创意版块：官方 vs 第三方 */
        .compare-cards {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
            gap: 1.6rem;
            margin-bottom: 4rem;
        }
        .compare-card {
            background: var(--bg-card);
            border: 1px solid var(--border-subtle);
            border-radius: var(--radius-md);
            padding: 2rem;
            backdrop-filter: blur(10px);
            transition: all var(--transition-smooth);
        }
        .compare-card.official {
            border-left: 5px solid #34d399;
        }
        .compare-card.unofficial {
            border-left: 5px solid #ef4444;
        }
        .compare-card h3 {
            font-size: 1.2rem;
            color: #fff;
            margin-bottom: 1rem;
            display: flex;
            align-items: center;
            gap: 0.5rem;
        }
        .compare-card ul {
            list-style: none;
            color: var(--text-secondary);
            font-size: 0.92rem;
            line-height: 1.8;
        }
        .compare-card ul li::before {
            content: "✓";
            color: #34d399;
            margin-right: 0.6rem;
            font-weight: bold;
        }
        .compare-card.unofficial ul li::before {
            content: "✗";
            color: #ef4444;
        }

        /* 哈希校验创意版块 */
        .hash-verify {
            background: var(--bg-card);
            border: 1px solid var(--border-subtle);
            border-radius: var(--radius-lg);
            padding: 2.5rem;
            backdrop-filter: blur(10px);
            margin-bottom: 4rem;
        }
        .hash-verify h3 {
            color: #fff;
            font-size: 1.35rem;
            margin-bottom: 1rem;
            display: flex;
            align-items: center;
            gap: 0.6rem;
        }
        .hash-verify p {
            color: var(--text-secondary);
            margin-bottom: 1.8rem;
        }
        .hash-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
            gap: 1rem;
        }
        .hash-item {
            background: rgba(255,255,255,0.03);
            border-radius: var(--radius-sm);
            padding: 1rem 1.2rem;
            border: 1px solid var(--border-subtle);
        }
        .hash-item .platform {
            font-weight: 650;
            color: #fff;
            font-size: 0.9rem;
            margin-bottom: 0.3rem;
        }
        .hash-item .hash-code {
            font-family: 'SF Mono', 'Fira Code', monospace;
            font-size: 0.75rem;
            color: var(--accent-sky);
            word-break: break-all;
            background: rgba(56,189,248,0.05);
            padding: 0.35rem 0.6rem;
            border-radius: 6px;
            display: inline-block;
            max-width: 100%;
        }

        /* 三步快速开始 */
        .steps-creative {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
            gap: 1.5rem;
            margin-bottom: 4rem;
        }
        .step-creative-card {
            background: var(--bg-card);
            border: 1px solid var(--border-subtle);
            border-radius: var(--radius-md);
            padding: 2rem 1.6rem;
            text-align: center;
            backdrop-filter: blur(10px);
            transition: all var(--transition-smooth);
        }
        .step-creative-card:hover {
            border-color: var(--border-active);
            transform: translateY(-4px);
            box-shadow: var(--shadow-glow-sky);
        }
        .step-creative-icon {
            font-size: 2rem;
            margin-bottom: 1rem;
            color: var(--accent-sky);
        }
        .step-creative-card h4 {
            color: #fff;
            font-size: 1.1rem;
            margin-bottom: 0.5rem;
        }
        .step-creative-card p {
            color: var(--text-secondary);
            font-size: 0.9rem;
        }

        /* 防窃听亮点 */
        .shield-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
            gap: 1.4rem;
        }
        .shield-card {
            background: var(--bg-card);
            border: 1px solid var(--border-subtle);
            border-radius: var(--radius-md);
            padding: 1.8rem;
            backdrop-filter: blur(10px);
            transition: all var(--transition-smooth);
        }
        .shield-card:hover {
            border-color: var(--border-active);
            box-shadow: var(--shadow-glow-sky);
        }
        .shield-card h4 {
            color: #fff;
            font-size: 1.05rem;
            margin-bottom: 0.5rem;
        }
        .shield-card p {
            color: var(--text-secondary);
            font-size: 0.9rem;
        }

        footer {
            background: rgba(4, 8, 16, 0.92);
            color: var(--text-tertiary);
            padding: 4rem 2rem 2.2rem 2rem;
            border-top: 1px solid var(--border-subtle);
            position: relative;
            z-index: 1;
        }
        .footer-container {
            max-width: 1200px;
            margin: 0 auto;
            display: flex;
            flex-direction: column;
            gap: 2.2rem;
        }
        .footer-links {
            display: flex;
            flex-wrap: wrap;
            gap: 2rem;
            justify-content: center;
        }
        .footer-links a {
            color: var(--text-tertiary);
            text-decoration: none;
            font-size: 0.88rem;
            transition: color 0.25s;
        }
        .footer-links a:hover {
            color: var(--accent-sky);
        }
        .footer-copyright {
            text-align: center;
            font-size: 0.83rem;
            border-top: 1px solid var(--border-subtle);
            padding-top: 2rem;
            color: #556278;
        }

        @media (max-width: 600px) {
            .hero h1 {
                font-size: 2rem;
            }
            .section-title {
                font-size: 1.6rem;
            }
            .btn {
                width: 100%;
            }
            .hash-code {
                font-size: 0.65rem;
            }
        }