* {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }

        body {
            font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
            background: #ffffff;
            color: #1a1a2e;
            line-height: 1.6;
        }

        a {
            text-decoration: none;
            color: inherit;
        }

        .container {
            max-width: 1140px;
            margin: 0 auto;
            padding: 0 32px;
        }

        /* ========== HEADER ========== */
        .header {
            background: rgba(255, 255, 255, 0.94);
            backdrop-filter: blur(10px);
            -webkit-backdrop-filter: blur(10px);
            border-bottom: 1px solid rgba(0, 0, 0, 0.04);
            position: sticky;
            top: 0;
            z-index: 100;
        }

        .header-inner {
            display: flex;
            align-items: center;
            justify-content: space-between;
            height: 68px;
        }

        .logo {
            display: flex;
            align-items: center;
            gap: 10px;
            font-size: 22px;
            font-weight: 800;
            color: #0f172a;
            letter-spacing: -0.3px;
            flex-shrink: 0;
        }

        .logo .mark {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            width: 34px;
            height: 34px;
            background: linear-gradient(145deg, #0d9488, #0f766e);
            border-radius: 8px;
            color: #fff;
            font-size: 16px;
            font-weight: 900;
            letter-spacing: 0;
        }

        .logo .badge {
            font-size: 11px;
            font-weight: 500;
            color: #0d9488;
            background: rgba(13, 148, 136, 0.10);
            padding: 2px 10px;
            border-radius: 20px;
            margin-left: 4px;
            letter-spacing: 0.2px;
        }

        .nav {
            display: flex;
            align-items: center;
            gap: 8px;
        }

        .nav a {
            font-size: 14px;
            font-weight: 500;
            color: #334155;
            padding: 6px 16px;
            border-radius: 30px;
            transition: all 0.2s;
        }

        .nav a:hover {
            background: rgba(13, 148, 136, 0.06);
            color: #0d9488;
        }

        .nav a.active {
            color: #0d9488;
            background: rgba(13, 148, 136, 0.08);
        }

        .nav .btn-solid {
            background: #0d9488;
            color: #fff;
            padding: 6px 22px;
            border-radius: 30px;
            font-weight: 600;
            font-size: 13px;
            transition: all 0.25s;
            border: none;
        }

        .nav .btn-solid:hover {
            background: #0f766e;
            transform: translateY(-1px);
            box-shadow: 0 4px 16px rgba(13, 148, 136, 0.3);
        }

        .mobile-toggle {
            display: none;
            flex-direction: column;
            gap: 5px;
            cursor: pointer;
            padding: 4px;
        }

        .mobile-toggle span {
            display: block;
            width: 26px;
            height: 2px;
            background: #1a1a2e;
            border-radius: 4px;
            transition: 0.3s;
        }

        /* ========== 页面头部 ========== */
        .page-head {
            padding: 48px 0 40px;
            background: linear-gradient(170deg, #f8fafc 0%, #ffffff 100%);
            border-bottom: 1px solid #e2e8f0;
            text-align: center;
        }

        .page-head h1 {
            font-size: 38px;
            font-weight: 800;
            color: #0f172a;
            letter-spacing: -0.02em;
            margin-bottom: 6px;
        }

        .page-head h1 .accent {
            color: #0d9488;
        }

        .page-head p {
            font-size: 17px;
            color: #64748b;
            max-width: 560px;
            margin: 0 auto;
        }

        .page-head .sub {
            margin-top: 12px;
            font-size: 14px;
            color: #94a3b8;
        }

        .page-head .sub strong {
            color: #0d9488;
            font-weight: 600;
        }

        /* ========== 下载卡片 ========== */
        .download-main {
            padding: 56px 0 72px;
            background: #ffffff;
        }

        .download-grid {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 24px;
            max-width: 920px;
            margin: 0 auto;
        }

        .download-card {
            display: grid;
            grid-template-columns: 60px 1fr auto;
            align-items: center;
            gap: 18px;
            background: #f8fafc;
            border-radius: 16px;
            padding: 18px 22px;
            border: 1px solid #f1f5f9;
            transition: all 0.25s;
            cursor: default;
        }

        .download-card:hover {
            border-color: #d1fae5;
            background: #f0fdfa;
            transform: translateY(-3px);
            box-shadow: 0 8px 24px rgba(13, 148, 136, 0.06);
        }

        .download-card .icon {
            font-size: 32px;
            text-align: center;
            line-height: 1;
        }

        .download-card .info .name {
            font-size: 17px;
            font-weight: 700;
            color: #0f172a;
        }

        .download-card .info .version {
            font-size: 13px;
            color: #94a3b8;
        }

        .download-card .info .size {
            font-size: 12px;
            color: #b0b8c8;
            margin-left: 6px;
        }

        .download-card .btn-down {
            background: #0d9488;
            color: #fff;
            padding: 8px 20px;
            border-radius: 50px;
            font-weight: 600;
            font-size: 13px;
            transition: all 0.25s;
            border: none;
            white-space: nowrap;
        }

        .download-card .btn-down:hover {
            background: #0f766e;
            transform: scale(1.02);
            box-shadow: 0 4px 16px rgba(13, 148, 136, 0.25);
        }

        .download-card .btn-down .arrow {
            display: inline-block;
            margin-left: 4px;
            transition: transform 0.2s;
        }

        .download-card .btn-down:hover .arrow {
            transform: translateX(3px);
        }

        .download-card .btn-down.android {
            background: #16a34a;
        }
        .download-card .btn-down.android:hover {
            background: #15803d;
            box-shadow: 0 4px 16px rgba(22, 163, 74, 0.25);
        }
        .download-card .btn-down.ios {
            background: #7c3aed;
        }
        .download-card .btn-down.ios:hover {
            background: #6d28d9;
            box-shadow: 0 4px 16px rgba(124, 58, 237, 0.25);
        }
        .download-card .btn-down.macos {
            background: #6b7280;
        }
        .download-card .btn-down.macos:hover {
            background: #4b5563;
            box-shadow: 0 4px 16px rgba(107, 114, 128, 0.25);
        }
        .download-card .btn-down.linux {
            background: #f59e0b;
            color: #1e293b;
        }
        .download-card .btn-down.linux:hover {
            background: #d97706;
            box-shadow: 0 4px 16px rgba(245, 158, 11, 0.25);
        }

        .linux-card {
            grid-column: 1 / -1;
        }

        /* 安全认证标识栏 */
        .download-note {
            max-width: 760px;
            margin: 40px auto 0;
            padding: 24px 32px;
            background: #f8fafc;
            border-radius: 16px;
            border: 1px solid #e2e8f0;
            display: grid;
            grid-template-columns: 1fr 1fr 1fr;
            gap: 20px;
            text-align: center;
        }

        .download-note .item .label {
            font-size: 13px;
            color: #94a3b8;
        }

        .download-note .item .value {
            font-size: 18px;
            font-weight: 700;
            color: #0f172a;
        }

        .download-note .item .value .highlight {
            color: #0d9488;
        }

        .download-note .divider {
            width: 1px;
            background: #e2e8f0;
            align-self: stretch;
        }

        .download-features {
            max-width: 820px;
            margin: 48px auto 0;
            display: grid;
            grid-template-columns: repeat(4, 1fr);
            gap: 20px;
            padding-top: 32px;
            border-top: 1px solid #e2e8f0;
        }

        .download-features .ft {
            text-align: center;
        }

        .download-features .ft .icon {
            font-size: 24px;
            margin-bottom: 4px;
        }

        .download-features .ft .label {
            font-size: 14px;
            font-weight: 500;
            color: #334155;
        }

        .download-features .ft .desc {
            font-size: 12px;
            color: #94a3b8;
        }

        /* ========== 创意版块1：正版认证与纯净安装 ========== */
        .cert-section {
            padding: 64px 0 72px;
            background: #fafdfc;
            border-top: 1px solid #e8f5f3;
        }

        .cert-head {
            text-align: center;
            max-width: 600px;
            margin: 0 auto 44px;
        }

        .cert-head h2 {
            font-size: 30px;
            font-weight: 800;
            color: #0f172a;
            letter-spacing: -0.01em;
            margin-bottom: 8px;
        }

        .cert-head h2 .accent {
            color: #0d9488;
        }

        .cert-head p {
            font-size: 16px;
            color: #64748b;
        }

        .cert-grid {
            display: grid;
            grid-template-columns: repeat(4, 1fr);
            gap: 20px;
        }

        .cert-card {
            background: #ffffff;
            border-radius: 18px;
            padding: 28px 20px;
            border: 1px solid #e2e8f0;
            text-align: center;
            transition: all 0.25s;
        }

        .cert-card:hover {
            border-color: #99f6e4;
            transform: translateY(-4px);
            box-shadow: 0 12px 32px rgba(13, 148, 136, 0.06);
        }

        .cert-card .cert-icon {
            font-size: 38px;
            margin-bottom: 14px;
        }

        .cert-card h4 {
            font-size: 16px;
            font-weight: 700;
            color: #0f172a;
            margin-bottom: 8px;
        }

        .cert-card p {
            font-size: 13px;
            color: #64748b;
            line-height: 1.6;
        }

        /* ========== 创意版块2：安装向导 ========== */
        .install-guide {
            padding: 64px 0 72px;
            background: #ffffff;
        }

        .install-head {
            text-align: center;
            max-width: 600px;
            margin: 0 auto 44px;
        }

        .install-head h2 {
            font-size: 30px;
            font-weight: 800;
            color: #0f172a;
            letter-spacing: -0.01em;
            margin-bottom: 8px;
        }

        .install-head h2 .accent {
            color: #0d9488;
        }

        .install-head p {
            font-size: 16px;
            color: #64748b;
        }

        .install-steps {
            max-width: 800px;
            margin: 0 auto;
            display: flex;
            flex-direction: column;
            gap: 24px;
        }

        .step {
            display: grid;
            grid-template-columns: 56px 1fr auto;
            gap: 18px;
            align-items: center;
            background: #f8fafc;
            border-radius: 16px;
            padding: 20px 24px;
            border: 1px solid #f1f5f9;
            transition: all 0.2s;
        }

        .step:hover {
            background: #f0fdfa;
            border-color: #d1fae5;
            transform: translateX(4px);
        }

        .step-number {
            font-size: 20px;
            font-weight: 800;
            color: #0d9488;
            background: rgba(13, 148, 136, 0.08);
            width: 44px;
            height: 44px;
            display: flex;
            align-items: center;
            justify-content: center;
            border-radius: 12px;
        }

        .step-content h4 {
            font-size: 17px;
            font-weight: 700;
            color: #0f172a;
            margin-bottom: 4px;
        }

        .step-content p {
            font-size: 14px;
            color: #64748b;
        }

        .step-visual {
            font-size: 36px;
            opacity: 0.9;
        }

        /* ========== 创意版块3：版本亮点 ========== */
        .whats-new {
            padding: 64px 0 72px;
            background: #f8fafc;
            border-top: 1px solid #e2e8f0;
        }

        .new-head {
            text-align: center;
            max-width: 640px;
            margin: 0 auto 44px;
        }

        .new-head h2 {
            font-size: 30px;
            font-weight: 800;
            color: #0f172a;
            letter-spacing: -0.01em;
            margin-bottom: 8px;
        }

        .new-head h2 .accent {
            color: #0d9488;
        }

        .new-head p {
            font-size: 16px;
            color: #64748b;
        }

        .new-grid {
            display: grid;
            grid-template-columns: repeat(4, 1fr);
            gap: 20px;
        }

        .new-card {
            background: #ffffff;
            border-radius: 16px;
            padding: 22px 18px;
            border: 1px solid #e2e8f0;
            transition: all 0.2s;
        }

        .new-card:hover {
            border-color: #99f6e4;
            transform: translateY(-3px);
            box-shadow: 0 10px 28px rgba(13, 148, 136, 0.06);
        }

        .new-card .new-badge {
            font-size: 28px;
            margin-bottom: 10px;
        }

        .new-card h4 {
            font-size: 16px;
            font-weight: 700;
            color: #0f172a;
            margin-bottom: 6px;
        }

        .new-card p {
            font-size: 13px;
            color: #64748b;
            line-height: 1.6;
        }

        .new-card p strong {
            color: #0d9488;
            font-weight: 700;
        }

        /* ========== CTA ========== */
        .cta-section {
            padding: 56px 0;
            background: #ffffff;
            border-top: 1px solid #e2e8f0;
        }

        .cta-box {
            display: grid;
            grid-template-columns: 2fr 1fr;
            gap: 40px;
            align-items: center;
            background: #f8fafc;
            border-radius: 24px;
            padding: 44px 48px;
            border: 1px solid #e2e8f0;
            box-shadow: 0 4px 24px rgba(0, 0, 0, 0.02);
        }

        .cta-box .text h3 {
            font-size: 26px;
            font-weight: 800;
            color: #0f172a;
            margin-bottom: 6px;
        }

        .cta-box .text p {
            font-size: 16px;
            color: #64748b;
        }

        .cta-box .action {
            text-align: right;
        }

        .btn-primary {
            display: inline-flex;
            align-items: center;
            gap: 8px;
            background: #0d9488;
            color: #fff;
            padding: 14px 36px;
            border-radius: 50px;
            font-weight: 600;
            font-size: 16px;
            transition: all 0.25s;
            border: none;
            box-shadow: 0 4px 20px rgba(13, 148, 136, 0.25);
            cursor: pointer;
        }

        .btn-primary:hover {
            background: #0f766e;
            transform: translateY(-2px);
            box-shadow: 0 8px 28px rgba(13, 148, 136, 0.35);
        }

        /* ========== FOOTER ========== */
        .footer {
            background: #0f172a;
            color: #e2e8f0;
            padding: 48px 0 28px;
        }

        .footer-grid {
            display: grid;
            grid-template-columns: 2fr 1fr 1fr 1.2fr;
            gap: 40px;
            margin-bottom: 32px;
        }

        .footer-brand .logo {
            color: #ffffff;
            margin-bottom: 12px;
            font-size: 20px;
        }

        .footer-brand .logo .mark {
            background: linear-gradient(145deg, #0d9488, #0f766e);
        }

        .footer-brand p {
            font-size: 14px;
            color: #94a3b8;
            max-width: 260px;
            line-height: 1.7;
        }

        .footer-brand .social {
            display: flex;
            gap: 14px;
            margin-top: 16px;
        }

        .footer-brand .social a {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            width: 36px;
            height: 36px;
            background: rgba(255, 255, 255, 0.06);
            border-radius: 50%;
            font-size: 16px;
            transition: all 0.2s;
            color: #94a3b8;
        }

        .footer-brand .social a:hover {
            background: rgba(13, 148, 136, 0.2);
            color: #0d9488;
        }

        .footer-col h4 {
            font-size: 14px;
            font-weight: 600;
            color: #f1f5f9;
            margin-bottom: 14px;
            letter-spacing: 0.3px;
        }

        .footer-col ul {
            list-style: none;
            display: flex;
            flex-direction: column;
            gap: 8px;
        }

        .footer-col ul a {
            font-size: 14px;
            color: #94a3b8;
            transition: color 0.2s;
        }

        .footer-col ul a:hover {
            color: #ffffff;
        }

        .footer-col.address {
            font-size: 14px;
            color: #94a3b8;
            line-height: 1.8;
        }

        .footer-col.address .label {
            font-weight: 500;
            color: #e2e8f0;
        }

        .footer-bottom {
            border-top: 1px solid rgba(255, 255, 255, 0.06);
            padding-top: 20px;
            display: flex;
            justify-content: space-between;
            align-items: center;
            flex-wrap: wrap;
            gap: 12px;
            font-size: 13px;
            color: #64748b;
        }

        .footer-bottom .links {
            display: flex;
            gap: 24px;
        }

        .footer-bottom .links a {
            color: #64748b;
            transition: color 0.2s;
            font-size: 13px;
        }

        .footer-bottom .links a:hover {
            color: #e2e8f0;
        }

        /* ========== 响应式 ========== */
        @media (max-width: 1024px) {
            .download-grid {
                grid-template-columns: 1fr 1fr;
            }
            .cert-grid {
                grid-template-columns: repeat(2, 1fr);
            }
            .new-grid {
                grid-template-columns: repeat(2, 1fr);
            }
            .cta-box {
                grid-template-columns: 1fr;
                text-align: center;
                padding: 36px 28px;
            }
            .cta-box .action {
                text-align: center;
            }
            .footer-grid {
                grid-template-columns: 1fr 1fr;
                gap: 32px;
            }
        }

        @media (max-width: 768px) {
            .nav {
                display: none;
                flex-direction: column;
                position: absolute;
                top: 68px;
                left: 0;
                right: 0;
                background: #ffffff;
                padding: 20px 28px;
                gap: 12px;
                border-bottom: 1px solid #e2e8f0;
                box-shadow: 0 8px 32px rgba(0, 0, 0, 0.06);
                align-items: stretch;
            }
            .nav.open {
                display: flex;
            }
            .nav a {
                padding: 10px 16px;
                text-align: center;
            }
            .nav .btn-solid {
                text-align: center;
                padding: 10px 16px;
            }
            .mobile-toggle {
                display: flex;
            }
            .page-head h1 {
                font-size: 28px;
            }
            .download-grid {
                grid-template-columns: 1fr;
                max-width: 480px;
            }
            .linux-card {
                grid-column: span 1;
            }
            .download-card {
                grid-template-columns: 48px 1fr auto;
                gap: 14px;
                padding: 14px 18px;
            }
            .download-note {
                grid-template-columns: 1fr;
                gap: 12px;
            }
            .download-note .divider {
                display: none;
            }
            .download-features {
                grid-template-columns: 1fr 1fr;
            }
            .cert-grid {
                grid-template-columns: 1fr 1fr;
            }
            .install-steps .step {
                grid-template-columns: 44px 1fr;
                gap: 12px;
                padding: 16px 18px;
            }
            .step-visual {
                display: none;
            }
            .new-grid {
                grid-template-columns: 1fr 1fr;
            }
            .footer-grid {
                grid-template-columns: 1fr;
                gap: 28px;
            }
            .footer-bottom {
                flex-direction: column;
                text-align: center;
            }
        }

        @media (max-width: 480px) {
            .container {
                padding: 0 18px;
            }
            .page-head {
                padding: 32px 0 28px;
            }
            .page-head h1 {
                font-size: 24px;
            }
            .download-main {
                padding: 36px 0 48px;
            }
            .download-card {
                grid-template-columns: 40px 1fr;
                gap: 12px;
                padding: 12px 14px;
            }
            .download-card .btn-down {
                grid-column: 2 / 3;
                justify-self: start;
                margin-top: 4px;
            }
            .cert-grid,
            .new-grid {
                grid-template-columns: 1fr;
            }
            .download-features {
                grid-template-columns: 1fr 1fr;
            }
            .install-steps .step {
                grid-template-columns: 36px 1fr;
                gap: 8px;
            }
            .step-number {
                width: 36px;
                height: 36px;
                font-size: 16px;
            }
        }