/* ========== 全局基础样式（与首页/产品中心一致） ========== */
        :root {
            --primary-color: #2563eb;
            --primary-hover: #1d4ed8;
            --primary-light: #dbeafe;
            --accent-gradient: linear-gradient(135deg, #2563eb 0%, #7c3aed 100%);
            --text-main: #111827;
            --text-muted: #4b5563;
            --text-light: #6b7280;
            --bg-light: #f9fafb;
            --bg-white: #ffffff;
            --border-color: #e5e7eb;
            --border-light: #f3f4f6;
            --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.06);
            --shadow-md: 0 4px 20px rgba(37, 99, 235, 0.08);
            --shadow-lg: 0 8px 40px rgba(0, 0, 0, 0.1);
            --radius-sm: 8px;
            --radius-md: 12px;
            --radius-lg: 20px;
            --radius-full: 50px;
            --transition: all 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; -moz-osx-font-smoothing: grayscale; }

        body {
            font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", "PingFang SC", "Microsoft YaHei", Arial, sans-serif;
            color: var(--text-main);
            line-height: 1.7;
            background-color: var(--bg-white);
            overflow-x: hidden;
        }

        a { text-decoration: none; color: inherit; transition: var(--transition); }

        .container { max-width: 1140px; margin: 0 auto; padding: 0 24px; }

        /* 顶部导航 */
        header {
            border-bottom: 1px solid var(--border-light);
            position: sticky; top: 0;
            background-color: rgba(255, 255, 255, 0.92);
            backdrop-filter: blur(20px);
            -webkit-backdrop-filter: blur(20px);
            z-index: 1000;
            transition: var(--transition);
        }
        header.scrolled { box-shadow: 0 2px 20px rgba(0, 0, 0, 0.06); }

        .nav-wrapper { display: flex; justify-content: space-between; align-items: center; height: 72px; gap: 20px; }

        .logo-container { display: flex; align-items: center; gap: 10px; flex-shrink: 0; }
        .logo-svg { width: 36px; height: 36px; filter: drop-shadow(0 2px 6px rgba(37, 99, 235, 0.3)); transition: var(--transition); }
        .logo-container:hover .logo-svg { transform: scale(1.05); }
        .logo-text { font-size: 22px; font-weight: 700; color: var(--primary-color); letter-spacing: -0.5px; white-space: nowrap; }
        .logo-text span { background: var(--accent-gradient); -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text; }

        nav ul { display: flex; list-style: none; gap: 22px; align-items: center; }
        nav a { font-weight: 500; color: var(--text-muted); font-size: 14px; transition: var(--transition); position: relative; padding: 6px 2px; white-space: nowrap; }
        nav a::after { content: ''; position: absolute; bottom: -2px; left: 50%; transform: translateX(-50%); width: 0; height: 2px; background: var(--accent-gradient); border-radius: 2px; transition: var(--transition); }
        nav a:hover, nav a.active { color: var(--primary-color); }
        nav a:hover::after, nav a.active::after { width: 100%; }

        /* ========== 下载中心 Hero ========== */
        .download-hero {
            background: linear-gradient(135deg, #0b1120 0%, #1e3a8a 50%, #2563eb 100%);
            color: #fff;
            padding: 90px 0 80px;
            text-align: center;
            position: relative;
            overflow: hidden;
        }
        .download-hero::before {
            content: '';
            position: absolute;
            top: -50%; left: -50%;
            width: 200%; height: 200%;
            background: radial-gradient(circle at 70% 30%, rgba(124, 58, 237, 0.15) 0%, transparent 50%);
            pointer-events: none;
            animation: heroPulse 6s ease-in-out infinite alternate;
        }
        @keyframes heroPulse {
            0% { transform: scale(1); opacity: 0.6; }
            100% { transform: scale(1.1); opacity: 1; }
        }
        .download-hero .container { position: relative; z-index: 2; }
        .download-hero h1 {
            font-size: 44px;
            font-weight: 800;
            letter-spacing: -1.5px;
            margin-bottom: 18px;
            background: linear-gradient(135deg, #ffffff 0%, #dbeafe 100%);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            background-clip: text;
        }
        .download-hero p {
            font-size: 18px;
            color: rgba(255,255,255,0.85);
            max-width: 750px;
            margin: 0 auto 30px;
            line-height: 1.8;
        }
        .hero-badge-download {
            display: inline-block;
            background: rgba(255,255,255,0.15);
            backdrop-filter: blur(10px);
            border: 1px solid rgba(255,255,255,0.25);
            color: #fff;
            padding: 6px 20px;
            border-radius: 50px;
            font-size: 13px;
            font-weight: 600;
            letter-spacing: 0.5px;
            margin-bottom: 28px;
        }
        .btn-white {
            display: inline-flex; align-items: center; gap: 10px;
            background: #fff; color: #2563eb; font-weight: 700;
            padding: 16px 40px; border-radius: var(--radius-full);
            font-size: 16px; transition: var(--transition);
            box-shadow: 0 8px 30px rgba(0,0,0,0.2);
        }
        .btn-white:hover { transform: translateY(-2px); box-shadow: 0 12px 40px rgba(0,0,0,0.3); }

        /* 通用 section */
        .section-title { text-align: center; font-size: 32px; margin-bottom: 14px; letter-spacing: -0.8px; font-weight: 800; color: var(--text-main); }
        .section-subtitle { text-align: center; font-size: 16px; color: var(--text-muted); max-width: 600px; margin: 0 auto 48px; line-height: 1.7; }

        /* ========== 平台下载卡片 ========== */
        .download-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
            gap: 30px;
            margin-top: 40px;
        }
        .download-card {
            background: #fff;
            border-radius: 24px;
            padding: 32px 24px;
            box-shadow: 0 10px 30px rgba(0,0,0,0.03);
            border: 1px solid #eef2f6;
            text-align: center;
            transition: all 0.3s ease;
            position: relative;
            overflow: hidden;
        }
        .download-card:hover {
            transform: translateY(-6px);
            box-shadow: 0 20px 40px rgba(37,99,235,0.12);
            border-color: #dbeafe;
        }
        .download-card::after {
            content: '';
            position: absolute;
            top: 0; left: 0; right: 0; height: 4px;
            background: var(--accent-gradient);
            opacity: 0; transition: opacity 0.3s;
        }
        .download-card:hover::after { opacity: 1; }
        .platform-icon {
            font-size: 48px;
            margin-bottom: 16px;
        }
        .download-card h3 {
            font-size: 20px;
            font-weight: 700;
            margin-bottom: 8px;
            color: #0f172a;
        }
        .download-card .version {
            font-size: 13px;
            color: #64748b;
            margin-bottom: 12px;
        }
        .download-card .file-info {
            font-size: 12px;
            color: #94a3b8;
            margin-bottom: 20px;
            display: flex;
            justify-content: center;
            gap: 16px;
        }
        .download-btn {
            display: inline-flex;
            align-items: center;
            gap: 8px;
            background: var(--accent-gradient);
            color: #fff;
            font-weight: 700;
            padding: 12px 28px;
            border-radius: var(--radius-full);
            font-size: 15px;
            transition: var(--transition);
            box-shadow: 0 4px 14px rgba(37, 99, 235, 0.25);
        }
        .download-btn:hover {
            transform: translateY(-2px);
            box-shadow: 0 8px 24px rgba(37, 99, 235, 0.35);
        }
        .badge-hot {
            background: #fee2e2;
            color: #dc2626;
            font-size: 11px;
            font-weight: 700;
            padding: 2px 10px;
            border-radius: 20px;
            display: inline-block;
            margin-left: 6px;
            vertical-align: middle;
        }

        /* ========== 安全校验版块 ========== */
        .security-check {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
            gap: 24px;
            margin-top: 40px;
        }
        .check-item {
            background: #fff;
            border-radius: 20px;
            padding: 28px 24px;
            text-align: center;
            border: 1px solid #eef2f6;
            transition: all 0.3s;
        }
        .check-item:hover {
            border-color: #bfdbfe;
            box-shadow: 0 12px 30px rgba(37,99,235,0.08);
        }
        .check-icon {
            font-size: 36px;
            margin-bottom: 16px;
        }
        .check-item h4 {
            font-size: 18px;
            font-weight: 700;
            margin-bottom: 8px;
            color: #0f172a;
        }
        .check-item p {
            font-size: 14px;
            color: #475569;
            line-height: 1.6;
        }

        /* ========== 版本更新日志 ========== */
        .changelog-list {
            max-width: 800px;
            margin: 40px auto 0;
        }
        .changelog-item {
            display: flex;
            gap: 20px;
            margin-bottom: 24px;
            background: #fff;
            border-radius: 16px;
            padding: 20px 24px;
            box-shadow: 0 4px 16px rgba(0,0,0,0.02);
            border: 1px solid #eef2f6;
        }
        .changelog-version {
            font-weight: 800;
            color: #2563eb;
            font-size: 16px;
            white-space: nowrap;
            min-width: 70px;
        }
        .changelog-details {
            flex: 1;
        }
        .changelog-details h5 {
            font-size: 16px;
            font-weight: 700;
            color: #0f172a;
            margin-bottom: 6px;
        }
        .changelog-details p {
            font-size: 14px;
            color: #64748b;
            line-height: 1.6;
        }

        /* ========== 系统要求表格 ========== */
        .requirements-table {
            width: 100%;
            border-collapse: collapse;
            margin-top: 40px;
            border-radius: var(--radius-md);
            overflow: hidden;
            box-shadow: var(--shadow-sm);
        }
        .requirements-table th, .requirements-table td {
            border: 1px solid var(--border-light);
            padding: 14px 18px;
            text-align: left;
            font-size: 14px;
        }
        .requirements-table th {
            background: linear-gradient(135deg, #f0f4ff 0%, #e8eeff 100%);
            font-weight: 700;
            color: var(--text-main);
        }
        .requirements-table tr:hover td {
            background-color: #fafbff;
        }

        /* ========== 下载步骤 ========== */
        .steps-download {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
            gap: 24px;
            text-align: center;
            margin-top: 40px;
        }
        .step-download-card {
            background: #fff;
            padding: 28px 20px;
            border-radius: 20px;
            border: 1px solid #eef2f6;
            transition: var(--transition);
        }
        .step-download-card:hover {
            box-shadow: var(--shadow-md);
            transform: translateY(-3px);
        }
        .step-number-download {
            width: 44px;
            height: 44px;
            background: var(--accent-gradient);
            color: #fff;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            margin: 0 auto 16px;
            font-weight: 800;
            font-size: 18px;
        }
        .step-download-card h4 {
            font-size: 17px;
            font-weight: 700;
            margin-bottom: 8px;
        }
        .step-download-card p {
            font-size: 14px;
            color: var(--text-muted);
        }

        /* ========== 页脚 ========== */
        footer {
            border-top: 1px solid var(--border-light);
            padding: 50px 0 30px;
            text-align: center;
            color: var(--text-muted);
            font-size: 13px;
            background-color: var(--bg-light);
        }
        .footer-links {
            margin-bottom: 20px;
            display: flex;
            flex-wrap: wrap;
            justify-content: center;
            gap: 14px;
        }
        .footer-links a {
            color: var(--text-muted);
            font-weight: 500;
            font-size: 13px;
            transition: var(--transition);
        }
        .footer-links a:hover { color: var(--primary-color); }
        .footer-brand {
            font-weight: 700;
            color: var(--text-main);
            font-size: 14px;
            margin-bottom: 6px;
        }
        .footer-domain {
            color: var(--text-light);
            font-size: 12px;
            margin-bottom: 16px;
        }

        /* ========== 响应式 ========== */
        @media (max-width: 1024px) {
            nav ul { gap: 14px; }
            nav a { font-size: 13px; }
            .download-hero h1 { font-size: 36px; }
        }
        @media (max-width: 768px) {
            .download-hero { padding: 60px 0 50px; }
            .download-hero h1 { font-size: 28px; letter-spacing: -0.5px; }
            .download-hero p { font-size: 16px; }
            .section-title { font-size: 24px; }
            nav ul { gap: 10px; overflow-x: auto; -webkit-overflow-scrolling: touch; padding-bottom: 4px; }
            nav a { font-size: 12px; white-space: nowrap; }
            .nav-wrapper { height: 60px; gap: 10px; }
            .logo-text { font-size: 18px; }
            .download-grid { grid-template-columns: 1fr; }
            .security-check { grid-template-columns: 1fr 1fr; }
            .changelog-item { flex-direction: column; gap: 8px; }
        }
        @media (max-width: 480px) {
            .download-hero h1 { font-size: 24px; }
            .download-hero p { font-size: 14px; }
            .logo-text { font-size: 16px; }
            .logo-svg { width: 28px; height: 28px; }
            .container { padding: 0 16px; }
            .security-check { grid-template-columns: 1fr; }
        }