:root {
            --primary: #0066cc;
            --primary-bright: #1a7dff;
            --primary-deep: #004d99;
            --primary-soft: #e8f3ff;
            --primary-glow: rgba(0, 102, 204, 0.18);
            --accent: #00a8b5;
            --accent-soft: #e0f7f9;
            --accent-glow: rgba(0, 168, 181, 0.16);
            --navy-deep: #060f1e;
            --navy: #0b1a30;
            --navy-mid: #0f2240;
            --navy-light: #152a4d;
            --text-primary: #0f172a;
            --text-secondary: #334155;
            --text-muted: #5f6b7a;
            --text-on-dark: #e2e8f0;
            --text-on-dark-muted: #94a3b8;
            --bg-white: #ffffff;
            --bg-slate: #f7f9fb;
            --bg-cool: #eef2f7;
            --border: #dde4ed;
            --border-light: #e8edf4;
            --shadow-xs: 0 1px 2px rgba(0, 0, 0, 0.03);
            --shadow-sm: 0 1px 4px rgba(0, 0, 0, 0.05);
            --shadow-md: 0 6px 22px rgba(0, 0, 0, 0.06);
            --shadow-lg: 0 14px 40px rgba(0, 0, 0, 0.08);
            --shadow-xl: 0 22px 56px rgba(0, 0, 0, 0.10);
            --radius-xs: 6px;
            --radius-sm: 10px;
            --radius: 16px;
            --radius-lg: 22px;
            --radius-xl: 30px;
            --radius-full: 9999px;
            --transition: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
            --transition-slow: 0.35s cubic-bezier(0.4, 0, 0.2, 1);
            --font-sans: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
        }
        *,
        *::before,
        *::after {
            box-sizing: border-box;
            margin: 0;
            padding: 0;
        }
        html {
            scroll-behavior: smooth;
            -webkit-text-size-adjust: 100%;
        }
        body {
            font-family: var(--font-sans);
            color: var(--text-primary);
            background-color: var(--bg-white);
            line-height: 1.6;
            overflow-x: hidden;
            -webkit-font-smoothing: antialiased;
            -moz-osx-font-smoothing: grayscale;
        }
        a {
            text-decoration: none;
            color: inherit;
            transition: color var(--transition);
        }
        img {
            max-width: 100%;
            height: auto;
            display: block;
        }
        .container {
            max-width: 1180px;
            margin: 0 auto;
            padding: 0 28px;
        }

        /* ========== HEADER (与首页一致) ========== */
        .header {
            position: absolute;
            top: 0;
            left: 0;
            right: 0;
            height: 84px;
            display: flex;
            align-items: center;
            z-index: 100;
            background: transparent;
            transition: background var(--transition), box-shadow var(--transition);
        }
        .header.scrolled {
            background: rgba(255, 255, 255, 0.94);
            backdrop-filter: blur(14px);
            -webkit-backdrop-filter: blur(14px);
            box-shadow: var(--shadow-sm);
            position: fixed;
        }
        .header-inner {
            display: flex;
            justify-content: space-between;
            align-items: center;
            width: 100%;
            gap: 32px;
        }
        .logo-area {
            display: flex;
            align-items: center;
            gap: 10px;
            flex-shrink: 0;
            transition: opacity var(--transition);
        }
        .logo-area:hover {
            opacity: 0.85;
        }
        .logo-icon {
            width: 34px;
            height: 34px;
            flex-shrink: 0;
            border-radius: 8px;
            background: linear-gradient(135deg, #0066cc 0%, #00a8b5 100%);
            display: flex;
            align-items: center;
            justify-content: center;
            color: #fff;
            font-weight: 900;
            font-size: 16px;
            letter-spacing: -0.5px;
            box-shadow: 0 2px 10px rgba(0, 102, 204, 0.25);
        }
        .logo-text {
            font-size: 20px;
            font-weight: 800;
            color: #0b1a30;
            letter-spacing: -0.3px;
            white-space: nowrap;
        }
        .logo-text .logo-accent {
            color: #0066cc;
        }
        .nav-list {
            display: flex;
            list-style: none;
            gap: 6px;
            flex-wrap: wrap;
            justify-content: center;
            align-items: center;
        }
        .nav-item {
            font-size: 14px;
            font-weight: 600;
            color: var(--text-primary);
            padding: 8px 15px;
            border-radius: 20px;
            transition: all var(--transition);
            white-space: nowrap;
        }
        .nav-item:hover {
            color: #0066cc;
            background: rgba(0, 102, 204, 0.05);
        }
        .nav-item.nav-cta {
            background: #0066cc;
            color: #fff;
            font-weight: 700;
            padding: 10px 20px;
            border-radius: 22px;
            margin-left: 2px;
            letter-spacing: 0.1px;
            box-shadow: 0 2px 10px rgba(0, 102, 204, 0.22);
        }
        .nav-item.nav-cta:hover {
            background: #004d99;
            color: #fff;
            box-shadow: 0 4px 16px rgba(0, 102, 204, 0.32);
            transform: translateY(-1px);
        }
        .mobile-menu-btn {
            display: none;
            background: none;
            border: none;
            cursor: pointer;
            padding: 8px;
            flex-shrink: 0;
        }
        .mobile-menu-btn span {
            display: block;
            width: 24px;
            height: 2.5px;
            background: #0b1a30;
            border-radius: 2px;
            margin: 5px 0;
            transition: all var(--transition);
        }

        /* ========== PAGE HEADER SECTION ========== */
        .page-hero {
            padding: 160px 0 70px;
            background: linear-gradient(160deg, #f0f6fc 0%, #e4eef8 25%, #f5f8fb 55%, #eaf3fa 100%);
            text-align: center;
            position: relative;
            overflow: hidden;
            isolation: isolate;
        }
        .page-hero::before {
            content: '';
            position: absolute;
            width: 500px;
            height: 500px;
            background: radial-gradient(circle at 50% 45%, rgba(0, 102, 204, 0.07) 0%, transparent 65%);
            top: -100px;
            right: -100px;
            border-radius: 50%;
            z-index: 0;
            pointer-events: none;
        }
        .page-hero .hero-content {
            position: relative;
            z-index: 1;
        }
        .page-hero .section-tag {
            display: inline-block;
            font-size: 12.5px;
            font-weight: 700;
            color: #0066cc;
            background: rgba(0, 102, 204, 0.06);
            padding: 6px 15px;
            border-radius: 18px;
            margin-bottom: 14px;
            letter-spacing: 0.4px;
            text-transform: uppercase;
        }
        .page-hero h1 {
            font-size: 42px;
            font-weight: 850;
            color: #060f1e;
            margin-bottom: 16px;
            letter-spacing: -0.5px;
        }
        .page-hero .subtitle {
            font-size: 16px;
            color: var(--text-secondary);
            max-width: 580px;
            margin: 0 auto 28px;
            line-height: 1.7;
        }
        .supported-badges {
            display: flex;
            flex-wrap: wrap;
            justify-content: center;
            gap: 12px;
            font-size: 13px;
            font-weight: 600;
            color: #334155;
        }
        .supported-badges span {
            background: #fff;
            padding: 8px 18px;
            border-radius: 20px;
            border: 1px solid var(--border-light);
            box-shadow: var(--shadow-xs);
        }

        /* ========== DOWNLOAD GRID ========== */
        .download-section {
            padding: 70px 0;
            background: var(--bg-white);
        }
        .download-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
            gap: 24px;
            margin-top: 30px;
        }
        .download-card {
            background: #fff;
            border: 1px solid var(--border-light);
            border-radius: var(--radius);
            padding: 34px 24px;
            text-align: center;
            transition: all var(--transition-slow);
            position: relative;
            overflow: hidden;
            display: flex;
            flex-direction: column;
            justify-content: space-between;
            cursor: pointer;
        }
        .download-card:hover {
            transform: translateY(-5px);
            box-shadow: var(--shadow-lg);
            border-color: transparent;
        }
        .download-card .os-icon {
            font-size: 54px;
            margin-bottom: 16px;
            display: block;
            line-height: 1;
            transition: transform var(--transition);
        }
        .download-card:hover .os-icon {
            transform: scale(1.05);
        }
        .download-card h3 {
            font-size: 20px;
            font-weight: 800;
            color: #060f1e;
            margin-bottom: 8px;
            letter-spacing: -0.3px;
        }
        .download-card .os-meta {
            font-size: 13px;
            color: var(--text-muted);
            margin-bottom: 16px;
            line-height: 1.5;
            min-height: 40px;
        }
        .download-card .btn-download {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            gap: 6px;
            padding: 12px 28px;
            font-size: 14px;
            font-weight: 700;
            color: #fff;
            background: #0066cc;
            border-radius: 24px;
            transition: all var(--transition);
            border: none;
            cursor: pointer;
            width: fit-content;
            margin: 0 auto;
            white-space: nowrap;
            box-shadow: 0 2px 10px rgba(0, 102, 204, 0.18);
        }
        .download-card .btn-download:hover {
            background: #004d99;
            box-shadow: 0 6px 20px rgba(0, 102, 204, 0.28);
        }
        .download-card .feature-tags {
            display: flex;
            flex-wrap: wrap;
            justify-content: center;
            gap: 8px;
            margin-top: 20px;
            font-size: 11px;
            font-weight: 600;
            color: #334155;
        }
        .download-card .feature-tags span {
            background: #f1f5f9;
            padding: 5px 12px;
            border-radius: 14px;
            white-space: nowrap;
        }

        /* ========== NEXT STEP SECTION ========== */
        .next-step-section {
            padding: 60px 0;
            background: var(--bg-slate);
            text-align: center;
        }
        .next-step-grid {
            display: flex;
            justify-content: center;
            gap: 24px;
            flex-wrap: wrap;
            margin-top: 28px;
        }
        .next-step-card {
            background: #fff;
            border: 1px solid var(--border-light);
            border-radius: var(--radius);
            padding: 28px 24px;
            width: 280px;
            transition: all var(--transition);
            text-decoration: none;
            color: inherit;
            display: block;
        }
        .next-step-card:hover {
            box-shadow: var(--shadow-md);
            border-color: #0066cc40;
            transform: translateY(-3px);
        }
        .next-step-card .step-icon {
            font-size: 30px;
            margin-bottom: 10px;
        }
        .next-step-card h4 {
            font-size: 16px;
            font-weight: 700;
            color: #060f1e;
            margin-bottom: 6px;
        }
        .next-step-card p {
            font-size: 13px;
            color: var(--text-muted);
        }

        /* ========== TROUBLESHOOTING ========== */
        .troubleshoot-section {
            padding: 70px 0;
            background: #fff;
        }
        .trouble-grid {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 28px;
            margin-top: 30px;
        }
        .trouble-card {
            background: #f9fbfd;
            border: 1px solid var(--border-light);
            border-radius: var(--radius);
            padding: 28px 24px;
            transition: all var(--transition);
        }
        .trouble-card:hover {
            border-color: #0066cc30;
            box-shadow: var(--shadow-sm);
        }
        .trouble-card h3 {
            font-size: 18px;
            font-weight: 750;
            color: #060f1e;
            margin-bottom: 10px;
        }
        .trouble-card ul {
            list-style: none;
            padding: 0;
            display: flex;
            flex-direction: column;
            gap: 8px;
        }
        .trouble-card ul li {
            font-size: 13.5px;
            color: var(--text-secondary);
            padding-left: 20px;
            position: relative;
        }
        .trouble-card ul li::before {
            content: '•';
            position: absolute;
            left: 4px;
            color: #0066cc;
            font-weight: 700;
        }

        /* ========== FAQ SECTION ========== */
        .faq-section {
            padding: 70px 0;
            background: var(--bg-slate);
        }
        .faq-list {
            max-width: 760px;
            margin: 30px auto 0;
            display: flex;
            flex-direction: column;
            gap: 12px;
        }
        .faq-item {
            background: #fff;
            border: 1px solid var(--border-light);
            border-radius: var(--radius-sm);
            padding: 20px 24px;
            transition: all var(--transition);
            cursor: pointer;
        }
        .faq-item:hover {
            border-color: #0066cc40;
            box-shadow: var(--shadow-sm);
        }
        .faq-item h3 {
            font-size: 15px;
            font-weight: 700;
            color: #060f1e;
            margin-bottom: 6px;
            letter-spacing: -0.1px;
        }
        .faq-item p {
            font-size: 13.5px;
            color: var(--text-muted);
            line-height: 1.6;
        }

        /* ========== FOOTER (与首页一致) ========== */
        .footer {
            padding: 40px 0;
            background: #060f1e;
            border-top: 1px solid #1a2d44;
            color: #64748b;
            font-size: 13px;
        }
        .footer-inner {
            display: flex;
            justify-content: space-between;
            align-items: center;
            flex-wrap: wrap;
            gap: 18px;
        }
        .footer-links {
            display: flex;
            gap: 20px;
            flex-wrap: wrap;
        }
        .footer-links a {
            color: #94a3b8;
            transition: color var(--transition);
            font-weight: 500;
            font-size: 12.5px;
        }
        .footer-links a:hover {
            color: #cbd5e1;
        }
        .footer-copy {
            font-size: 12px;
            color: #556577;
        }

        /* ========== RESPONSIVE ========== */
        @media (max-width: 1100px) {
            .header {
                position: relative;
                height: auto;
                padding: 14px 0;
                background: #fff;
                border-bottom: 1px solid var(--border-light);
            }
            .header-inner {
                flex-direction: row;
                flex-wrap: wrap;
                gap: 10px;
                justify-content: space-between;
            }
            .mobile-menu-btn {
                display: block;
            }
            .nav-list {
                display: none;
                flex-direction: column;
                width: 100%;
                gap: 2px;
                padding-top: 8px;
            }
            .nav-list.open {
                display: flex;
            }
            .nav-item {
                font-size: 13px;
                padding: 10px 14px;
                width: 100%;
                text-align: center;
                border-radius: 8px;
            }
            .nav-item.nav-cta {
                margin-left: 0;
                margin-top: 6px;
            }
            .page-hero {
                padding: 60px 0 50px;
            }
            .page-hero h1 {
                font-size: 30px;
            }
            .trouble-grid {
                grid-template-columns: 1fr;
            }
            .download-grid {
                grid-template-columns: 1fr 1fr;
            }
        }
        @media (max-width: 640px) {
            .download-grid {
                grid-template-columns: 1fr;
            }
            .page-hero h1 {
                font-size: 24px;
            }
            .supported-badges span {
                font-size: 11px;
                padding: 6px 12px;
            }
            .next-step-card {
                width: 100%;
            }
        }