:root {
            --bg-deep: #020617;
            --bg-surface: #0a0f1f;
            --bg-glass: rgba(10, 16, 34, 0.7);
            --border-subtle: rgba(56, 189, 248, 0.18);
            --border-glow: rgba(56, 189, 248, 0.45);
            --accent-sky: #38bdf8;
            --accent-violet: #818cf8;
            --accent-emerald: #34d399;
            --accent-amber: #fbbf24;
            --accent-rose: #fb7185;
            --text-head: #f1f5f9;
            --text-body: #b0bec5;
            --text-muted: #64748b;
            --radius-sm: 10px;
            --radius-md: 16px;
            --radius-lg: 22px;
            --radius-xl: 28px;
            --transition-fast: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
            --transition-smooth: 0.35s cubic-bezier(0.4, 0, 0.2, 1);
        }

        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            font-family: "PingFang SC", "Hiragino Sans GB", "Segoe UI", -apple-system, BlinkMacSystemFont, "Microsoft YaHei", sans-serif;
        }

        html {
            scroll-behavior: smooth;
        }

        body {
            background: var(--bg-deep);
            color: var(--text-body);
            line-height: 1.65;
            overflow-x: hidden;
            position: relative;
            -webkit-font-smoothing: antialiased;
            -moz-osx-font-smoothing: grayscale;
        }

        .mesh-bg {
            position: fixed;
            inset: 0;
            pointer-events: none;
            z-index: -3;
            background-image:
                linear-gradient(to right, rgba(56, 189, 248, 0.04) 1px, transparent 1px),
                linear-gradient(to bottom, rgba(56, 189, 248, 0.04) 1px, transparent 1px);
            background-size: 44px 44px;
            mask-image: radial-gradient(ellipse 70% 60% at 50% 35%, black 20%, transparent 75%);
            -webkit-mask-image: radial-gradient(ellipse 70% 60% at 50% 35%, black 20%, transparent 75%);
        }

        .ambient-glow-top {
            position: fixed;
            top: -280px;
            left: 50%;
            transform: translateX(-50%);
            width: 900px;
            height: 650px;
            background: radial-gradient(circle, rgba(129, 140, 248, 0.12) 0%, rgba(56, 189, 248, 0.06) 35%, transparent 70%);
            filter: blur(90px);
            pointer-events: none;
            z-index: -2;
            animation: breatheGlow 7s ease-in-out infinite;
        }

        .ambient-glow-bottom {
            position: fixed;
            bottom: -200px;
            right: -150px;
            width: 600px;
            height: 500px;
            background: radial-gradient(circle, rgba(52, 211, 153, 0.08) 0%, transparent 70%);
            filter: blur(80px);
            pointer-events: none;
            z-index: -2;
            animation: breatheGlow 9s ease-in-out infinite reverse;
        }

        @keyframes breatheGlow {
            0%,
            100% {
                opacity: 0.7;
            }
            50% {
                opacity: 1;
            }
        }

        /* 导航栏 (与首页一致) */
        header {
            position: sticky;
            top: 0;
            z-index: 1000;
            background: rgba(2, 6, 23, 0.75);
            backdrop-filter: blur(18px);
            -webkit-backdrop-filter: blur(18px);
            border-bottom: 1px solid rgba(255, 255, 255, 0.06);
            transition: var(--transition-smooth);
        }

        .nav-container {
            max-width: 1320px;
            margin: 0 auto;
            padding: 0.9rem 2rem;
            display: flex;
            align-items: center;
            justify-content: space-between;
            gap: 2rem;
        }

        .brand-logo {
            display: flex;
            align-items: center;
            gap: 0.7rem;
            text-decoration: none;
            flex-shrink: 0;
        }

        .logo-icon {
            width: 40px;
            height: 40px;
            background: linear-gradient(135deg, var(--accent-sky), var(--accent-violet));
            border-radius: 11px;
            display: flex;
            align-items: center;
            justify-content: center;
            box-shadow: 0 0 18px rgba(56, 189, 248, 0.45);
            transition: var(--transition-smooth);
        }

        .brand-logo:hover .logo-icon {
            box-shadow: 0 0 28px rgba(129, 140, 248, 0.7);
            transform: scale(1.04);
        }

        .logo-text {
            font-size: 1.35rem;
            font-weight: 900;
            letter-spacing: -0.4px;
            background: linear-gradient(90deg, #f1f5f9, #cbd5e1);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            background-clip: text;
        }

        .nav-links {
            display: flex;
            gap: 1.6rem;
            list-style: none;
            flex-wrap: wrap;
            justify-content: center;
        }

        .nav-links a {
            color: var(--text-body);
            text-decoration: none;
            font-size: 0.9rem;
            font-weight: 500;
            padding: 0.4rem 0.6rem;
            border-radius: 6px;
            transition: var(--transition-fast);
            white-space: nowrap;
            position: relative;
        }

        .nav-links a::after {
            content: '';
            position: absolute;
            bottom: -2px;
            left: 50%;
            transform: translateX(-50%) scaleX(0);
            width: 60%;
            height: 2px;
            background: var(--accent-sky);
            border-radius: 2px;
            transition: transform var(--transition-smooth);
        }

        .nav-links a:hover,
        .nav-links a.active {
            color: var(--accent-sky);
        }
        .nav-links a:hover::after,
        .nav-links a.active::after {
            transform: translateX(-50%) scaleX(1);
        }

        .nav-actions .btn-neon {
            background: linear-gradient(135deg, var(--accent-sky), var(--accent-violet));
            color: #fff;
            padding: 0.55rem 1.3rem;
            border-radius: 25px;
            text-decoration: none;
            font-size: 0.88rem;
            font-weight: 600;
            box-shadow: 0 0 22px rgba(56, 189, 248, 0.35);
            transition: var(--transition-smooth);
            border: 1px solid rgba(255, 255, 255, 0.18);
            white-space: nowrap;
            letter-spacing: 0.3px;
        }
        .nav-actions .btn-neon:hover {
            transform: translateY(-3px);
            box-shadow: 0 8px 32px rgba(129, 140, 248, 0.55);
        }

        /* 通用区块 */
        .section-container {
            max-width: 1320px;
            margin: 0 auto 5.5rem;
            padding: 0 2rem;
        }
        .section-header {
            text-align: center;
            margin-bottom: 3rem;
        }
        .section-title {
            font-size: 2.1rem;
            color: #fff;
            font-weight: 800;
            margin-bottom: 0.7rem;
            letter-spacing: -0.3px;
        }
        .section-subtitle {
            color: var(--text-body);
            max-width: 620px;
            margin: 0 auto;
            font-size: 0.95rem;
        }

        /* ========== 下载页面特有 Hero ========== */
        .download-hero {
            max-width: 1320px;
            margin: 3rem auto 4.5rem;
            padding: 0 2rem;
            display: grid;
            grid-template-columns: 1fr 0.9fr;
            gap: 3rem;
            align-items: center;
        }
        .hero-badge {
            display: inline-flex;
            align-items: center;
            gap: 0.5rem;
            background: rgba(250, 204, 21, 0.09);
            border: 1px solid rgba(250, 204, 21, 0.3);
            color: var(--accent-amber);
            padding: 0.3rem 1rem;
            border-radius: 99px;
            font-size: 0.82rem;
            font-weight: 600;
            margin-bottom: 1.3rem;
            letter-spacing: 0.4px;
        }
        .hero-title-dl {
            font-size: 2.9rem;
            font-weight: 900;
            line-height: 1.18;
            color: var(--text-head);
            margin-bottom: 1rem;
        }
        .hero-title-dl span {
            background: linear-gradient(135deg, var(--accent-sky), var(--accent-violet));
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            background-clip: text;
        }
        .hero-desc-dl {
            font-size: 1rem;
            color: var(--text-body);
            margin-bottom: 1.8rem;
            max-width: 520px;
        }

        .version-card {
            background: var(--bg-glass);
            border: 1px solid var(--border-subtle);
            border-radius: var(--radius-xl);
            padding: 1.8rem 2rem;
            backdrop-filter: blur(14px);
            box-shadow: 0 15px 40px rgba(0,0,0,0.4);
            text-align: center;
        }
        .version-num {
            font-size: 3.8rem;
            font-weight: 900;
            color: #fff;
            font-family: 'SF Mono', 'JetBrains Mono', monospace;
            line-height: 1;
        }
        .version-tag {
            display: inline-block;
            background: rgba(52, 211, 153, 0.12);
            border: 1px solid rgba(52, 211, 153, 0.35);
            color: var(--accent-emerald);
            padding: 0.2rem 0.8rem;
            border-radius: 99px;
            font-size: 0.78rem;
            font-weight: 700;
            margin: 0.5rem 0 1rem;
        }
        .version-meta {
            font-size: 0.85rem;
            color: var(--text-muted);
            display: flex;
            justify-content: center;
            gap: 1.2rem;
        }

        /* ========== 系统选择卡片 ========== */
        .os-grid {
            display: grid;
            grid-template-columns: repeat(5, 1fr);
            gap: 1.2rem;
            margin-top: 2rem;
        }
        .os-card {
            background: var(--bg-glass);
            border: 1px solid var(--border-subtle);
            border-radius: var(--radius-lg);
            padding: 1.8rem 1rem;
            text-align: center;
            transition: var(--transition-smooth);
            cursor: pointer;
            text-decoration: none;
            color: inherit;
            display: flex;
            flex-direction: column;
            align-items: center;
            gap: 0.8rem;
        }
        .os-card:hover {
            transform: translateY(-5px);
            border-color: var(--border-glow);
            box-shadow: 0 12px 28px rgba(56, 189, 248, 0.15);
        }
        .os-icon {
            width: 52px;
            height: 52px;
            border-radius: 14px;
            background: rgba(56, 189, 248, 0.08);
            display: flex;
            align-items: center;
            justify-content: center;
            transition: var(--transition-smooth);
        }
        .os-card:hover .os-icon {
            background: rgba(56, 189, 248, 0.18);
            box-shadow: 0 0 18px rgba(56, 189, 248, 0.35);
        }
        .os-card h3 {
            color: #fff;
            font-size: 0.95rem;
            font-weight: 700;
        }
        .os-card .dl-tag {
            font-size: 0.72rem;
            background: rgba(255,255,255,0.05);
            padding: 0.2rem 0.7rem;
            border-radius: 99px;
            color: var(--accent-sky);
            border: 1px solid rgba(255,255,255,0.1);
            margin-top: 0.2rem;
        }

        /* ========== 更新日志时间线 ========== */
        .changelog-timeline {
            position: relative;
            padding-left: 2.5rem;
            margin-top: 2rem;
        }
        .changelog-timeline::before {
            content: '';
            position: absolute;
            left: 1rem;
            top: 0;
            bottom: 0;
            width: 2px;
            background: linear-gradient(180deg, var(--accent-sky), var(--accent-violet), transparent);
        }
        .log-entry {
            position: relative;
            margin-bottom: 2.2rem;
            background: var(--bg-glass);
            border: 1px solid var(--border-subtle);
            border-radius: var(--radius-md);
            padding: 1.5rem 1.8rem;
            backdrop-filter: blur(10px);
        }
        .log-entry::before {
            content: '';
            position: absolute;
            left: -2.1rem;
            top: 1.5rem;
            width: 12px;
            height: 12px;
            background: var(--accent-sky);
            border-radius: 50%;
            box-shadow: 0 0 12px var(--accent-sky);
        }
        .log-version {
            font-size: 1.1rem;
            font-weight: 800;
            color: #fff;
            display: flex;
            align-items: center;
            gap: 0.7rem;
            margin-bottom: 0.6rem;
        }
        .log-date {
            font-size: 0.78rem;
            color: var(--text-muted);
            font-weight: 400;
        }
        .log-list {
            list-style: none;
            padding-left: 0;
        }
        .log-list li {
            margin-bottom: 0.45rem;
            font-size: 0.88rem;
            color: var(--text-body);
            display: flex;
            align-items: baseline;
            gap: 0.5rem;
        }
        .log-list li::before {
            content: '▹';
            color: var(--accent-emerald);
            font-weight: bold;
        }

        /* ========== 安装三部曲 ========== */
        .steps-grid {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 2rem;
            margin-top: 2rem;
        }
        .step-card {
            background: var(--bg-glass);
            border: 1px solid var(--border-subtle);
            border-radius: var(--radius-lg);
            padding: 2rem 1.5rem;
            text-align: center;
            transition: var(--transition-smooth);
            position: relative;
        }
        .step-card:hover {
            border-color: var(--border-glow);
            box-shadow: 0 14px 32px rgba(56, 189, 248, 0.12);
        }
        .step-number {
            width: 44px;
            height: 44px;
            border-radius: 50%;
            background: linear-gradient(135deg, var(--accent-sky), var(--accent-violet));
            color: #fff;
            font-weight: 900;
            font-size: 1.3rem;
            display: flex;
            align-items: center;
            justify-content: center;
            margin: 0 auto 1.2rem;
            box-shadow: 0 0 18px rgba(56, 189, 248, 0.4);
        }
        .step-card h3 {
            color: #fff;
            font-size: 1.1rem;
            margin-bottom: 0.5rem;
        }
        .step-card p {
            font-size: 0.85rem;
            color: var(--text-body);
        }

        /* ========== 创意版块：下载加速承诺 ========== */
        .speed-promise {
            background: linear-gradient(135deg, rgba(11, 19, 43, 0.85), rgba(15, 23, 42, 0.8));
            border: 1px solid var(--border-subtle);
            border-radius: var(--radius-xl);
            padding: 2.5rem;
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 2.5rem;
            align-items: center;
        }
        .promise-stat {
            text-align: center;
            background: rgba(2, 6, 23, 0.6);
            border-radius: var(--radius-md);
            padding: 2rem;
        }
        .promise-stat .big-num {
            font-size: 3.8rem;
            font-weight: 900;
            color: var(--accent-emerald);
            font-family: 'SF Mono', 'JetBrains Mono', monospace;
            line-height: 1;
        }
        .promise-stat .big-num-sub {
            font-size: 0.9rem;
            color: var(--text-muted);
            margin-top: 0.3rem;
        }

        /* Footer (与首页一致) */
        footer {
            background: #01040e;
            border-top: 1px solid rgba(255, 255, 255, 0.06);
            padding: 4rem 2rem 2rem;
        }
        .footer-wrap {
            max-width: 1320px;
            margin: 0 auto;
            display: grid;
            grid-template-columns: 2fr repeat(3, 1fr);
            gap: 3rem;
            margin-bottom: 3rem;
        }
        .footer-brand p {
            font-size: 0.87rem;
            color: var(--text-muted);
            margin-top: 1rem;
            max-width: 320px;
        }
        .footer-col h4 {
            color: #fff;
            font-size: 0.9rem;
            margin-bottom: 1.1rem;
            text-transform: uppercase;
            letter-spacing: 0.6px;
        }
        .footer-col ul {
            list-style: none;
        }
        .footer-col li {
            margin-bottom: 0.6rem;
        }
        .footer-col a {
            color: var(--text-body);
            text-decoration: none;
            font-size: 0.86rem;
            transition: color var(--transition-fast);
        }
        .footer-col a:hover {
            color: var(--accent-sky);
        }
        .footer-bottom {
            max-width: 1320px;
            margin: 0 auto;
            padding-top: 2rem;
            border-top: 1px solid rgba(255, 255, 255, 0.04);
            display: flex;
            justify-content: space-between;
            font-size: 0.82rem;
            color: var(--text-muted);
            flex-wrap: wrap;
            gap: 0.8rem;
        }

        /* 响应式 */
        @media (max-width: 1100px) {
            .download-hero {
                grid-template-columns: 1fr;
            }
            .os-grid {
                grid-template-columns: repeat(3, 1fr);
            }
            .steps-grid {
                grid-template-columns: 1fr 1fr;
            }
            .speed-promise {
                grid-template-columns: 1fr;
            }
            .footer-wrap {
                grid-template-columns: 1fr 1fr;
            }
        }
        @media (max-width: 680px) {
            .os-grid {
                grid-template-columns: repeat(2, 1fr);
            }
            .steps-grid {
                grid-template-columns: 1fr;
            }
            .footer-wrap {
                grid-template-columns: 1fr;
            }
            .nav-links {
                gap: 0.8rem;
            }
            .hero-title-dl {
                font-size: 2rem;
            }
        }