* {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }
        body {
            font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
            background: #f5f7fa;
            color: #1a1a2e;
            line-height: 1.6;
        }
        a {
            text-decoration: none;
            color: inherit;
        }
        .container {
            max-width: 1200px;
            margin: 0 auto;
            padding: 0 24px;
        }

        /* Header (与首页一致) */
        header {
            background: #0f0f1a;
            color: #fff;
            padding: 16px 0;
            position: sticky;
            top: 0;
            z-index: 100;
            border-bottom: 1px solid #2a2a3e;
        }
        .header-inner {
            display: flex;
            align-items: center;
            justify-content: space-between;
            flex-wrap: wrap;
            gap: 12px;
        }
        .logo {
            font-size: 26px;
            font-weight: 700;
            letter-spacing: 1px;
            display: flex;
            align-items: center;
            gap: 10px;
        }
        .logo svg {
            width: 32px;
            height: 32px;
            color: #6c5ce7;
            flex-shrink: 0;
        }
        .logo span {
            color: #6c5ce7;
        }
        .logo small {
            font-size: 14px;
            font-weight: 400;
            color: #a0a0b8;
            margin-left: 8px;
            letter-spacing: 0.5px;
        }
        nav {
            display: flex;
            align-items: center;
            gap: 28px;
            flex-wrap: wrap;
        }
        nav a {
            font-size: 15px;
            color: #c8c8e0;
            transition: color 0.2s;
            position: relative;
        }
        nav a:hover {
            color: #fff;
        }
        nav a.active {
            color: #6c5ce7;
            font-weight: 600;
        }
        .nav-download {
            background: #6c5ce7;
            color: #fff !important;
            padding: 8px 22px;
            border-radius: 30px;
            font-weight: 600;
            font-size: 14px;
            transition: background 0.2s;
        }
        .nav-download:hover {
            background: #5a4bd1;
            color: #fff !important;
        }

        .nav-toggle {
            display: none;
            flex-direction: column;
            gap: 4px;
            cursor: pointer;
            background: none;
            border: none;
            padding: 4px;
        }
        .nav-toggle span {
            display: block;
            width: 26px;
            height: 2px;
            background: #c8c8e0;
            border-radius: 2px;
            transition: 0.2s;
        }

        /* Hero */
        .download-hero {
            padding: 60px 0 50px;
            background: linear-gradient(145deg, #0f0f1a 0%, #1a1a30 100%);
            color: #fff;
            border-bottom: 1px solid #2a2a3e;
            text-align: center;
        }
        .download-hero h1 {
            font-size: 40px;
            font-weight: 800;
            margin-bottom: 12px;
        }
        .download-hero h1 .highlight {
            color: #6c5ce7;
        }
        .download-hero p {
            font-size: 18px;
            color: #b0b0ca;
            max-width: 600px;
            margin: 0 auto 8px;
        }

        /* 全局高亮 */
        .highlight {
            color: #6c5ce7;
        }

        /* 系统要求卡片 */
        .requirements {
            padding: 20px 0 40px;
            background: #f5f7fa;
            border-top: 1px solid #eaeaef;
        }
        .requirements .container {
            display: flex;
            flex-wrap: wrap;
            gap: 40px;
            justify-content: center;
        }
        .req-block {
            flex: 1 1 200px;
            min-width: 160px;
            background: #fff;
            padding: 24px 28px;
            border-radius: 20px;
            border: 1px solid #eaeaef;
            text-align: center;
        }
        .req-block h4 {
            font-size: 16px;
            font-weight: 700;
            color: #1a1a2e;
            margin-bottom: 6px;
        }
        .req-block p {
            font-size: 14px;
            color: #666688;
            margin: 0;
        }
        .req-block .os-icon {
            font-size: 28px;
            display: block;
            margin-bottom: 8px;
        }

        /* 下载卡片区 */
        .download-section {
            padding: 60px 0 40px;
            background: #f5f7fa;
        }
        .download-grid {
            display: grid;
            grid-template-columns: repeat(4, 1fr);
            gap: 30px;
            margin-top: 10px;
        }
        .download-card {
            background: #fff;
            border-radius: 24px;
            padding: 36px 24px 30px;
            text-align: center;
            border: 1px solid #eaeaef;
            transition: transform 0.3s, box-shadow 0.3s, border-color 0.3s;
            display: flex;
            flex-direction: column;
            align-items: center;
            position: relative;
        }
        .download-card:hover {
            transform: translateY(-8px);
            box-shadow: 0 20px 60px rgba(0, 0, 0, 0.07);
            border-color: #6c5ce7;
        }
        .download-card .platform-icon {
            width: 80px;
            height: 80px;
            border-radius: 20px;
            display: flex;
            align-items: center;
            justify-content: center;
            margin-bottom: 18px;
            flex-shrink: 0;
            transition: transform 0.3s;
        }
        .download-card:hover .platform-icon {
            transform: scale(1.05);
        }
        .download-card .platform-icon svg {
            width: 44px;
            height: 44px;
            stroke-width: 1.8;
        }
        .download-card h3 {
            font-size: 22px;
            font-weight: 700;
            margin-bottom: 4px;
            color: #1a1a2e;
        }
        .download-card .version {
            font-size: 14px;
            color: #8888aa;
            margin-bottom: 2px;
        }
        .download-card .size {
            font-size: 13px;
            color: #9999bb;
            margin-bottom: 20px;
        }
        .download-card .btn-download {
            background: #6c5ce7;
            color: #fff;
            height: 48px;
            line-height: 48px;
            padding: 0 16px;
            border-radius: 30px;
            font-weight: 600;
            font-size: 15px;
            border: none;
            cursor: pointer;
            transition: background 0.25s, transform 0.15s, box-shadow 0.2s;
            display: inline-flex;
            align-items: center;
            justify-content: center;
            gap: 8px;
            width: 100%;
            white-space: nowrap;
            box-shadow: 0 2px 8px rgba(108, 92, 231, 0.2);
        }
        .download-card .btn-download:hover {
            background: #5a4bd1;
            transform: scale(1.02);
            box-shadow: 0 4px 14px rgba(108, 92, 231, 0.35);
        }
        .download-card .btn-download:active {
            transform: scale(0.97);
        }
        .download-card .badge-os {
            position: absolute;
            top: 16px;
            right: 16px;
            background: #f0f0f5;
            color: #666688;
            font-size: 11px;
            padding: 2px 14px;
            border-radius: 20px;
            font-weight: 500;
            letter-spacing: 0.3px;
        }

        /* 平台专属颜色 */
        .card-windows .platform-icon { background: #e8f0fe; }
        .card-windows .platform-icon svg { color: #0078d4; }
        .card-windows .badge-os { background: #e8f0fe; color: #0078d4; }

        .card-macos .platform-icon { background: #f0f0f5; }
        .card-macos .platform-icon svg { color: #555577; }
        .card-macos .badge-os { background: #f0f0f5; color: #555577; }

        .card-android .platform-icon { background: #e8f5e9; }
        .card-android .platform-icon svg { color: #3ddc84; }
        .card-android .badge-os { background: #e8f5e9; color: #2e7d32; }

        .card-ios .platform-icon { background: #fce8e6; }
        .card-ios .platform-icon svg { color: #ea4335; }
        .card-ios .badge-os { background: #fce8e6; color: #c62828; }

        /* 历史版本入口 */
        .history-link {
            text-align: center;
            margin-top: 30px;
        }
        .history-link a {
            color: #6c5ce7;
            font-weight: 500;
            font-size: 15px;
            border-bottom: 1px dashed #6c5ce7;
        }
        .history-link a:hover {
            border-bottom-style: solid;
        }

        /* 安装流程 */
        .install-guide {
            padding: 40px 0 60px;
            background: #fff;
        }
        .section-title {
            text-align: center;
            font-size: 30px;
            font-weight: 700;
            margin-bottom: 12px;
            color: #1a1a2e;
        }
        .section-sub {
            text-align: center;
            color: #666688;
            max-width: 560px;
            margin: 0 auto 40px;
            font-size: 17px;
        }
        .steps {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 32px;
        }
        .step-item {
            background: #f8f9fc;
            border-radius: 20px;
            padding: 32px 28px 28px;
            border: 1px solid #eaeaef;
            text-align: center;
            transition: border-color 0.25s;
        }
        .step-item:hover {
            border-color: #6c5ce7;
        }
        .step-number {
            width: 48px;
            height: 48px;
            background: #6c5ce7;
            color: #fff;
            font-size: 20px;
            font-weight: 700;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            margin: 0 auto 16px;
        }
        .step-item h4 {
            font-size: 18px;
            font-weight: 700;
            margin-bottom: 8px;
        }
        .step-item p {
            font-size: 15px;
            color: #666688;
            line-height: 1.7;
        }

        /* 安全下载须知 */
        .security-tip {
            padding: 30px 0 50px;
            background: #f5f7fa;
            border-top: 1px solid #eaeaef;
        }
        .security-tip .container {
            display: flex;
            flex-wrap: wrap;
            align-items: center;
            justify-content: center;
            gap: 30px;
            background: #fff;
            padding: 32px 40px;
            border-radius: 24px;
            border: 1px solid #eaeaef;
        }
        .security-tip .tip-icon {
            font-size: 42px;
            line-height: 1;
        }
        .security-tip .tip-text {
            flex: 1;
            min-width: 200px;
        }
        .security-tip .tip-text h4 {
            font-size: 18px;
            font-weight: 700;
            margin-bottom: 4px;
        }
        .security-tip .tip-text p {
            color: #666688;
            font-size: 15px;
            margin: 0;
        }

        /* CTA */
        .cta {
            padding: 60px 0 70px;
            background: #0f0f1a;
            color: #fff;
            text-align: center;
        }
        .cta h2 {
            font-size: 32px;
            font-weight: 700;
            margin-bottom: 12px;
        }
        .cta p {
            color: #b0b0ca;
            font-size: 17px;
            max-width: 500px;
            margin: 0 auto 28px;
        }
        .cta .btn-primary {
            background: #6c5ce7;
            color: #fff;
            padding: 14px 44px;
            border-radius: 30px;
            font-weight: 600;
            font-size: 17px;
            border: none;
            cursor: pointer;
            transition: background 0.25s;
            display: inline-flex;
            align-items: center;
            gap: 8px;
        }
        .cta .btn-primary:hover {
            background: #5a4bd1;
        }

        /* Footer */
        footer {
            background: #0a0a14;
            color: #8888aa;
            padding: 40px 0 30px;
            border-top: 1px solid #1a1a2e;
        }
        .footer-inner {
            display: grid;
            grid-template-columns: 2fr 1fr 1fr 1fr;
            gap: 40px;
        }
        .footer-brand .logo {
            font-size: 22px;
            margin-bottom: 10px;
        }
        .footer-brand p {
            font-size: 14px;
            max-width: 260px;
            line-height: 1.7;
        }
        .footer-col h4 {
            color: #e0e0f0;
            font-size: 16px;
            margin-bottom: 14px;
            font-weight: 600;
        }
        .footer-col a {
            display: block;
            font-size: 14px;
            color: #8888aa;
            margin-bottom: 8px;
            transition: color 0.2s;
        }
        .footer-col a:hover {
            color: #fff;
        }
        .footer-bottom {
            border-top: 1px solid #1a1a2e;
            padding-top: 20px;
            margin-top: 30px;
            display: flex;
            justify-content: space-between;
            flex-wrap: wrap;
            gap: 10px;
            font-size: 13px;
        }

        /* 响应式 */
        @media (max-width: 1024px) {
            .download-grid {
                grid-template-columns: repeat(2, 1fr);
                gap: 24px;
            }
            .steps {
                grid-template-columns: repeat(2, 1fr);
            }
        }
        @media (max-width: 768px) {
            nav {
                display: none;
                width: 100%;
                flex-direction: column;
                align-items: flex-start;
                gap: 14px;
                padding: 16px 0 8px;
                border-top: 1px solid #2a2a3e;
                margin-top: 12px;
            }
            nav.open {
                display: flex;
            }
            .nav-toggle {
                display: flex;
            }
            .download-hero h1 {
                font-size: 30px;
            }
            .download-grid {
                grid-template-columns: 1fr 1fr;
                gap: 18px;
            }
            .download-card {
                padding: 28px 16px 24px;
            }
            .download-card .platform-icon {
                width: 64px;
                height: 64px;
            }
            .download-card .platform-icon svg {
                width: 34px;
                height: 34px;
            }
            .download-card h3 {
                font-size: 18px;
            }
            .download-card .btn-download {
                height: 44px;
                line-height: 44px;
                font-size: 14px;
                white-space: normal;
            }
            .requirements .container {
                gap: 16px;
            }
            .req-block {
                flex: 1 1 140px;
                padding: 18px 16px;
            }
            .steps {
                grid-template-columns: 1fr;
                gap: 18px;
            }
            .footer-inner {
                grid-template-columns: 1fr 1fr;
                gap: 24px;
            }
            .cta h2 {
                font-size: 26px;
            }
            .security-tip .container {
                padding: 24px 20px;
                flex-direction: column;
                text-align: center;
            }
        }
        @media (max-width: 480px) {
            .download-grid {
                grid-template-columns: 1fr;
                max-width: 360px;
                margin: 0 auto;
            }
            .download-hero {
                padding: 40px 0 30px;
            }
            .download-hero h1 {
                font-size: 26px;
            }
            .container {
                padding: 0 16px;
            }
            .footer-inner {
                grid-template-columns: 1fr;
                gap: 20px;
            }
            .section-title {
                font-size: 24px;
            }
        }