:root {
            --brand: #0066ff;
            --brand-deep: #0044cc;
            --brand-glow: #3399ff;
            --accent: #ff6b35;
            --surface-0: #ffffff;
            --surface-1: #f7f9fc;
            --surface-2: #eef3f9;
            --text-strong: #0a0f1a;
            --text-body: #2a3344;
            --text-muted: #5e6b80;
            --border: #dde4ef;
            --border-light: #eaf0f7;
            --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.04);
            --shadow-md: 0 8px 28px rgba(0, 0, 0, 0.07);
            --shadow-lg: 0 20px 48px rgba(0, 0, 0, 0.10);
            --radius-sm: 12px;
            --radius: 18px;
            --radius-lg: 26px;
            --radius-xl: 36px;
            --transition: 0.28s cubic-bezier(0.4, 0, 0.2, 1);
            --font-stack: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", Roboto, Helvetica, Arial, sans-serif;
        }
        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }
        html {
            scroll-behavior: smooth;
        }
        body {
            font-family: var(--font-stack);
            background: var(--surface-0);
            color: var(--text-body);
            line-height: 1.65;
            -webkit-font-smoothing: antialiased;
            -moz-osx-font-smoothing: grayscale;
            overflow-x: hidden;
        }
        a {
            color: inherit;
            text-decoration: none;
            transition: var(--transition);
        }
        .container {
            max-width: 1240px;
            margin: 0 auto;
            padding: 0 28px;
        }

        /* 导航栏（与首页统一） */
        .header {
            position: sticky;
            top: 0;
            z-index: 120;
            background: rgba(255, 255, 255, 0.88);
            backdrop-filter: saturate(180%) blur(18px);
            -webkit-backdrop-filter: saturate(180%) blur(18px);
            border-bottom: 1px solid var(--border-light);
            padding: 14px 0;
            transition: var(--transition);
        }
        .header-inner {
            display: flex;
            align-items: center;
            justify-content: space-between;
            gap: 16px;
            flex-wrap: wrap;
        }
        .logo-group {
            display: flex;
            align-items: center;
            gap: 10px;
            flex-shrink: 0;
        }
        .logo-icon {
            width: 38px;
            height: 38px;
            flex-shrink: 0;
        }
        .logo-text {
            font-weight: 750;
            font-size: 24px;
            letter-spacing: -0.4px;
            color: var(--text-strong);
            white-space: nowrap;
        }
        .logo-text .accent-dot {
            color: var(--brand);
        }
        .logo-badge {
            font-size: 11px;
            font-weight: 600;
            background: var(--brand);
            color: #fff;
            padding: 3px 10px;
            border-radius: 30px;
            letter-spacing: 0.3px;
            white-space: nowrap;
        }
        .nav {
            display: flex;
            align-items: center;
            gap: 26px;
            flex-wrap: wrap;
        }
        .nav a {
            font-size: 15px;
            font-weight: 530;
            color: var(--text-body);
            position: relative;
            padding: 6px 0;
            white-space: nowrap;
        }
        .nav a:hover {
            color: var(--brand);
        }
        .nav a.active {
            color: var(--brand);
            font-weight: 650;
        }
        .nav a.active::after {
            content: '';
            position: absolute;
            left: 0;
            bottom: -2px;
            width: 100%;
            height: 2.5px;
            background: var(--brand);
            border-radius: 4px;
        }
        .nav-pill {
            background: var(--brand);
            color: #fff !important;
            font-size: 13px;
            padding: 7px 16px !important;
            border-radius: 40px;
            font-weight: 600;
            letter-spacing: 0.2px;
        }
        .nav-pill:hover {
            background: var(--brand-deep) !important;
            color: #fff !important;
            transform: translateY(-1px);
            box-shadow: 0 6px 18px rgba(0, 102, 255, 0.28);
        }
        .mobile-toggle {
            display: none;
            flex-direction: column;
            gap: 5px;
            background: none;
            border: none;
            cursor: pointer;
            padding: 6px;
            z-index: 130;
        }
        .mobile-toggle span {
            display: block;
            width: 26px;
            height: 2.5px;
            background: var(--text-strong);
            border-radius: 4px;
            transition: 0.25s;
        }

        /* 页面头部 */
        .page-hero {
            padding: 50px 0 36px;
            background: linear-gradient(165deg, #f4f8ff 0%, #ffffff 30%, #f9fbff 100%);
            border-bottom: 1px solid var(--border-light);
            text-align: center;
        }
        .page-hero h1 {
            font-size: 42px;
            font-weight: 800;
            letter-spacing: -0.025em;
            color: var(--text-strong);
            margin-bottom: 10px;
        }
        .page-hero .subhead {
            font-size: 17px;
            color: var(--text-muted);
            max-width: 600px;
            margin: 0 auto 18px;
            line-height: 1.6;
        }
        .hero-tags {
            display: flex;
            flex-wrap: wrap;
            justify-content: center;
            gap: 12px;
            font-size: 13px;
            color: var(--text-muted);
        }
        .hero-tags span {
            background: var(--surface-2);
            padding: 5px 14px;
            border-radius: 30px;
            font-weight: 540;
        }
        .hero-tags span.em {
            background: #e8f0ff;
            color: var(--brand);
            font-weight: 630;
        }

        /* 智能检测卡片 */
        .detect-section {
            padding: 40px 0 48px;
            background: var(--surface-0);
        }
        .detect-card {
            background: #fff;
            border-radius: var(--radius-xl);
            border: 1px solid var(--border-light);
            padding: 34px 30px;
            display: flex;
            align-items: center;
            justify-content: space-between;
            gap: 24px;
            flex-wrap: wrap;
            box-shadow: var(--shadow-md);
            transition: var(--transition);
            position: relative;
            overflow: hidden;
        }
        .detect-card::before {
            content: '';
            position: absolute;
            top: -40px;
            right: -40px;
            width: 160px;
            height: 160px;
            background: radial-gradient(circle, rgba(0, 102, 255, 0.06) 0%, transparent 70%);
            border-radius: 50%;
            pointer-events: none;
        }
        .detect-left {
            display: flex;
            align-items: center;
            gap: 18px;
            flex-wrap: wrap;
            position: relative;
            z-index: 1;
        }
        .detect-icon {
            font-size: 48px;
            line-height: 1;
        }
        .detect-info h3 {
            font-size: 22px;
            font-weight: 700;
            color: var(--text-strong);
            margin-bottom: 4px;
        }
        .detect-info .os-name {
            font-size: 16px;
            color: var(--brand);
            font-weight: 650;
            letter-spacing: 0.2px;
        }
        .detect-info .detect-hint {
            font-size: 13px;
            color: var(--text-muted);
            margin-top: 4px;
        }
        .detect-right {
            display: flex;
            flex-wrap: wrap;
            gap: 12px;
            position: relative;
            z-index: 1;
        }
        .btn {
            display: inline-flex;
            align-items: center;
            gap: 8px;
            padding: 14px 30px;
            border-radius: 50px;
            font-weight: 620;
            font-size: 15px;
            border: none;
            cursor: pointer;
            transition: var(--transition);
            white-space: nowrap;
            letter-spacing: 0.2px;
        }
        .btn-primary {
            background: var(--brand);
            color: #fff;
            box-shadow: 0 8px 24px rgba(0, 102, 255, 0.26);
        }
        .btn-primary:hover {
            background: var(--brand-deep);
            transform: translateY(-3px);
            box-shadow: 0 14px 34px rgba(0, 102, 255, 0.34);
        }
        .btn-outline {
            background: transparent;
            color: var(--text-strong);
            border: 1.8px solid #c8d4e6;
        }
        .btn-outline:hover {
            border-color: var(--brand);
            color: var(--brand);
            background: #f6faff;
        }
        .detect-manual {
            font-size: 13px;
            color: var(--text-muted);
            margin-top: 6px;
            text-align: right;
            position: relative;
            z-index: 1;
        }
        .detect-manual a {
            color: var(--brand);
            font-weight: 600;
            text-decoration: underline;
            text-underline-offset: 2px;
        }

        /* 全平台卡片 */
        .platforms-section {
            padding: 52px 0 60px;
            background: var(--surface-1);
            border-top: 1px solid var(--border-light);
        }
        .section-header {
            text-align: center;
            margin-bottom: 38px;
        }
        .section-header h2 {
            font-size: 32px;
            font-weight: 750;
            letter-spacing: -0.025em;
            color: var(--text-strong);
            margin-bottom: 8px;
        }
        .section-header .section-sub {
            font-size: 16px;
            color: var(--text-muted);
            max-width: 520px;
            margin: 0 auto;
            line-height: 1.6;
        }
        .platform-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
            gap: 24px;
        }
        .platform-card {
            background: #fff;
            padding: 28px 18px 22px;
            border-radius: var(--radius-lg);
            border: 1px solid var(--border-light);
            text-align: center;
            transition: var(--transition);
            box-shadow: var(--shadow-sm);
        }
        .platform-card:hover {
            border-color: #c0d4f0;
            box-shadow: var(--shadow-md);
            transform: translateY(-5px);
        }
        .platform-card .plat-icon {
            font-size: 40px;
            margin-bottom: 10px;
            display: block;
        }
        .platform-card h4 {
            font-size: 17px;
            font-weight: 680;
            color: var(--text-strong);
            margin-bottom: 4px;
        }
        .platform-card .plat-ver {
            font-size: 12px;
            color: var(--text-muted);
            margin-bottom: 14px;
        }
        .btn-small {
            display: inline-block;
            padding: 10px 24px;
            border-radius: 40px;
            font-weight: 600;
            font-size: 13px;
            background: var(--brand);
            color: #fff;
            transition: var(--transition);
            white-space: nowrap;
        }
        .btn-small:hover {
            background: var(--brand-deep);
            box-shadow: 0 6px 18px rgba(0, 102, 255, 0.25);
        }
        .btn-small.router {
            background: #2a3344;
        }
        .btn-small.router:hover {
            background: #0a0f1a;
        }

        /* 信任数据指标版块 */
        .trust-metrics {
            padding: 40px 0;
            background: var(--surface-0);
            border-top: 1px solid var(--border-light);
        }
        .metrics-grid {
            display: grid;
            grid-template-columns: repeat(4, 1fr);
            gap: 22px;
        }
        .metric-item {
            text-align: center;
            padding: 20px 15px;
            background: #fff;
            border-radius: var(--radius-lg);
            border: 1px solid var(--border-light);
            transition: var(--transition);
        }
        .metric-item:hover {
            box-shadow: var(--shadow-md);
        }
        .metric-num {
            font-size: 38px;
            font-weight: 850;
            letter-spacing: -0.03em;
            color: var(--brand);
            line-height: 1;
            margin-bottom: 6px;
        }
        .metric-item p {
            font-size: 14px;
            color: var(--text-muted);
        }

        /* 下载步骤版块 */
        .steps-section {
            padding: 48px 0 56px;
            background: var(--surface-1);
            border-top: 1px solid var(--border-light);
            border-bottom: 1px solid var(--border-light);
        }
        .steps-grid {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 24px;
        }
        .step-item {
            background: #fff;
            border-radius: var(--radius-lg);
            padding: 26px 22px;
            border: 1px solid var(--border-light);
            position: relative;
            text-align: center;
            transition: var(--transition);
        }
        .step-item:hover {
            box-shadow: var(--shadow-md);
            border-color: #b8cce8;
        }
        .step-num {
            display: inline-block;
            width: 40px;
            height: 40px;
            border-radius: 50%;
            background: var(--brand);
            color: #fff;
            font-weight: 750;
            font-size: 18px;
            line-height: 40px;
            margin-bottom: 10px;
        }
        .step-item h4 {
            font-size: 17px;
            font-weight: 680;
            color: var(--text-strong);
            margin-bottom: 4px;
        }
        .step-item p {
            font-size: 13px;
            color: var(--text-muted);
            line-height: 1.5;
        }

        /* 新用户加速横幅 */
        .offer-strip {
            background: linear-gradient(140deg, #0a0f1a 0%, #121f36 40%, #0d1528 100%);
            border-radius: var(--radius-xl);
            padding: 32px 30px;
            color: #fff;
            display: flex;
            align-items: center;
            justify-content: space-between;
            gap: 20px;
            flex-wrap: wrap;
            margin-bottom: 40px;
            position: relative;
            overflow: hidden;
        }
        .offer-strip::before {
            content: '';
            position: absolute;
            top: -50px;
            right: -30px;
            width: 180px;
            height: 180px;
            background: radial-gradient(circle, rgba(0, 102, 255, 0.35) 0%, transparent 70%);
            border-radius: 50%;
            pointer-events: none;
        }
        .offer-text h3 {
            font-size: 24px;
            font-weight: 750;
            letter-spacing: -0.02em;
            margin-bottom: 4px;
            position: relative;
            z-index: 1;
        }
        .offer-text p {
            font-size: 14px;
            color: #b0c0d8;
            position: relative;
            z-index: 1;
        }
        .offer-text .highlight-offer {
            color: #ffb347;
            font-weight: 700;
        }
        .btn-offer {
            background: #fff;
            color: #0a0f1a;
            font-weight: 680;
            padding: 14px 30px;
            border-radius: 50px;
            font-size: 15px;
            transition: var(--transition);
            position: relative;
            z-index: 1;
            white-space: nowrap;
        }
        .btn-offer:hover {
            background: #ffb347;
            color: #0a0f1a;
            transform: translateY(-2px);
            box-shadow: 0 10px 28px rgba(255, 179, 71, 0.35);
        }

        /* Footer（与首页统一） */
        .footer {
            background: #0a0f1a;
            color: #b0c0d8;
            padding: 44px 0 28px;
            border-top: 1px solid #1a2333;
        }
        .footer-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
            gap: 30px;
            margin-bottom: 28px;
        }
        .footer-col h5 {
            color: #ffffff;
            font-size: 15px;
            font-weight: 640;
            margin-bottom: 10px;
            letter-spacing: 0.2px;
        }
        .footer-col ul {
            list-style: none;
            padding: 0;
        }
        .footer-col ul li {
            font-size: 13px;
            line-height: 2;
            color: #8899b4;
        }
        .footer-col a {
            color: #8899b4;
        }
        .footer-col a:hover {
            color: #ffffff;
        }
        .footer-bottom {
            border-top: 1px solid #1a2333;
            padding-top: 18px;
            display: flex;
            flex-wrap: wrap;
            justify-content: space-between;
            gap: 12px;
            font-size: 12px;
            color: #6a7d94;
        }
        .footer-bottom .meta-row {
            display: flex;
            flex-wrap: wrap;
            gap: 16px;
        }

        /* 响应式 */
        @media (max-width: 1024px) {
            .metrics-grid {
                grid-template-columns: 1fr 1fr;
            }
            .steps-grid {
                grid-template-columns: 1fr 1fr 1fr;
            }
        }
        @media (max-width: 768px) {
            .nav {
                display: none;
                width: 100%;
                flex-direction: column;
                align-items: flex-start;
                gap: 12px;
                padding: 14px 0 6px;
                border-top: 1px solid var(--border-light);
                margin-top: 8px;
            }
            .nav.open {
                display: flex;
            }
            .mobile-toggle {
                display: flex;
            }
            .page-hero h1 {
                font-size: 30px;
            }
            .detect-card {
                flex-direction: column;
                align-items: flex-start;
                gap: 18px;
            }
            .detect-manual {
                text-align: left;
            }
            .platform-grid {
                grid-template-columns: 1fr 1fr;
            }
            .metrics-grid {
                grid-template-columns: 1fr 1fr;
            }
            .steps-grid {
                grid-template-columns: 1fr;
            }
            .offer-strip {
                flex-direction: column;
                text-align: center;
                padding: 24px 20px;
            }
        }
        @media (max-width: 480px) {
            .container {
                padding: 0 14px;
            }
            .page-hero h1 {
                font-size: 26px;
            }
            .platform-grid {
                grid-template-columns: 1fr;
            }
            .detect-left {
                flex-direction: column;
                text-align: center;
                width: 100%;
            }
            .detect-right {
                width: 100%;
                justify-content: center;
            }
            .btn {
                padding: 12px 22px;
                font-size: 14px;
            }
            .footer-grid {
                grid-template-columns: 1fr 1fr;
            }
            .footer-bottom {
                flex-direction: column;
                gap: 6px;
            }
            .logo-text {
                font-size: 20px;
            }
            .metrics-grid {
                grid-template-columns: 1fr 1fr;
                gap: 12px;
            }
        }