:root {
            --ztdk-primary: #4285F4;
            --ztdk-red: #EA4335;
            --ztdk-yellow: #FBBC05;
            --ztdk-green: #34A853;
            --ztdk-text-dark: #202124;
            --ztdk-text-light: #5f6368;
            --ztdk-bg-gray: #f8f9fa;
            --ztdk-white: #ffffff;
            --ztdk-transition: all 0.4s cubic-bezier(0.165, 0.84, 0.44, 1);
        }

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

        body {
            font-family: "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Hiragino Sans GB", sans-serif;
            color: var(--ztdk-text-dark);
            line-height: 1.6;
            background-color: var(--ztdk-white);
            overflow-x: hidden;
        }

        /* 导航栏样式 */
        .ztdk-header {
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            z-index: 1000;
            background: rgba(255, 255, 255, 0.9);
            backdrop-filter: blur(15px);
            border-bottom: 1px solid rgba(0,0,0,0.05);
        }

        .ztdk-nav-container {
            max-width: 1400px;
            margin: 0 auto;
            display: flex;
            flex-wrap: wrap;
            align-items: center;
            justify-content: space-between;
            padding: 0 24px;
            height: 72px;
        }

        .ztdk-logo {
            display: flex;
            align-items: center;
            min-width: 0;
        }

        .ztdk-logo img {
            height: 32px;
            width: auto;
        }

        .ztdk-nav-menu {
            display: flex;
            flex-wrap: wrap;
            list-style: none;
            gap: 8px;
            min-width: 0;
        }

        .ztdk-nav-item {
            position: relative;
            min-width: 0;
        }

        .ztdk-nav-link {
            display: block;
            padding: 8px 16px;
            text-decoration: none;
            color: var(--ztdk-text-light);
            font-weight: 500;
            font-size: 0.95rem;
            transition: var(--ztdk-transition);
            white-space: nowrap;
        }

        /* 动态光迹效果 */
        .ztdk-nav-link::after {
            content: '';
            position: absolute;
            bottom: 0;
            left: 50%;
            width: 0;
            height: 2px;
            background: linear-gradient(90deg, var(--ztdk-primary), var(--ztdk-red), var(--ztdk-yellow), var(--ztdk-green));
            transition: var(--ztdk-transition);
            transform: translateX(-50%);
        }

        .ztdk-nav-link:hover::after,
        .ztdk-nav-link.ztdk-active::after {
            width: 80%;
        }

        .ztdk-nav-link:hover {
            color: var(--ztdk-primary);
        }

        .ztdk-nav-link.ztdk-active {
            color: var(--ztdk-primary);
            background: rgba(66, 133, 244, 0.05);
            border-radius: 20px;
        }

        /* Hero 区设计 - 独特对角线分割与流体视觉 */
        .ztdk-hero {
            padding-top: 140px;
            padding-bottom: 96px;
            background: radial-gradient(circle at 90% 10%, rgba(66, 133, 244, 0.08) 0%, transparent 40%),
                        radial-gradient(circle at 10% 90%, rgba(52, 168, 83, 0.08) 0%, transparent 40%);
            position: relative;
            overflow: hidden;
        }

        .ztdk-container-wide {
            max-width: 1400px;
            margin: 0 auto;
            padding: 0 48px;
        }

        .ztdk-hero-content {
            display: flex;
            flex-wrap: wrap;
            align-items: center;
            gap: 64px;
        }

        .ztdk-hero-text {
            flex: 1;
            min-width: 320px;
            word-break: break-word;
        }

        .ztdk-hero-title {
            font-size: clamp(2.5rem, 5vw + 1rem, 4.5rem);
            line-height: 1.1;
            font-weight: 800;
            margin-bottom: 24px;
            letter-spacing: -0.02em;
            background: linear-gradient(135deg, #202124 0%, #4285F4 100%);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
        }

        .ztdk-hero-subtitle {
            font-size: clamp(1.1rem, 1.5vw + 0.5rem, 1.4rem);
            color: var(--ztdk-text-light);
            margin-bottom: 40px;
            max-width: 600px;
            line-height: 1.6;
        }

        .ztdk-hero-visual {
            flex: 1.2;
            min-width: 320px;
            position: relative;
            display: flex;
            justify-content: center;
        }

        /* 3D 风格同步演示框 */
        .ztdk-sync-box {
            width: 100%;
            max-width: 600px;
            height: 400px;
            background: var(--ztdk-white);
            border-radius: 32px;
            box-shadow: 0 40px 80px rgba(0,0,0,0.1);
            position: relative;
            transform: perspective(1000px) rotateY(-5deg);
            display: flex;
            align-items: center;
            justify-content: center;
            border: 1px solid rgba(0,0,0,0.05);
        }

        .ztdk-floating-card {
            position: absolute;
            background: var(--ztdk-white);
            padding: 16px;
            border-radius: 16px;
            box-shadow: 0 10px 30px rgba(0,0,0,0.08);
            display: flex;
            align-items: center;
            gap: 12px;
            animation: float 4s ease-in-out infinite;
        }

        @keyframes float {
            0%, 100% { transform: translateY(0); }
            50% { transform: translateY(-20px); }
        }

        /* 下载卡片区域 */
        .ztdk-download-section {
            padding: 96px 0;
            background-color: var(--ztdk-bg-gray);
        }

        .ztdk-section-header {
            text-align: center;
            margin-bottom: 64px;
            padding: 0 24px;
        }

        .ztdk-section-title {
            font-size: 2.5rem;
            margin-bottom: 16px;
            font-weight: 700;
        }

        .ztdk-download-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
            gap: 32px;
        }

        .ztdk-card {
            background: var(--ztdk-white);
            padding: 40px;
            border-radius: 24px;
            transition: var(--ztdk-transition);
            border: 1px solid transparent;
            display: flex;
            flex-direction: column;
            align-items: flex-start;
            min-width: 0;
            word-break: break-word;
        }

        .ztdk-card:hover {
            transform: translateY(-12px);
            box-shadow: 0 24px 48px rgba(0,0,0,0.06);
            border-color: var(--ztdk-primary);
        }

        .ztdk-card-icon {
            width: 64px;
            height: 64px;
            border-radius: 16px;
            margin-bottom: 24px;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 2rem;
            background: var(--ztdk-bg-gray);
        }

        .ztdk-card-tag {
            font-size: 0.75rem;
            font-weight: 700;
            text-transform: uppercase;
            padding: 4px 12px;
            border-radius: 20px;
            margin-bottom: 12px;
            background: rgba(66, 133, 244, 0.1);
            color: var(--ztdk-primary);
        }

        .ztdk-btn {
            display: inline-block;
            padding: 14px 32px;
            border-radius: 30px;
            font-weight: 600;
            text-decoration: none;
            transition: var(--ztdk-transition);
            cursor: pointer;
            border: none;
            font-size: 1rem;
            margin-top: auto;
        }

        .ztdk-btn-primary {
            background: var(--ztdk-primary);
            color: white;
        }

        .ztdk-btn-primary:hover {
            background: #1a73e8;
            box-shadow: 0 4px 12px rgba(66, 133, 244, 0.3);
        }

        /* 杂志级节奏感区块 */
        .ztdk-feature-split {
            display: flex;
            flex-wrap: wrap;
            align-items: center;
            padding: 80px 0;
            gap: 64px;
        }

        .ztdk-feature-split.ztdk-reverse {
            flex-direction: row-reverse;
        }

        .ztdk-feature-image {
            flex: 1;
            min-width: 320px;
            background: linear-gradient(135deg, #f1f3f4 0%, #e8eaed 100%);
            border-radius: 32px;
            height: 450px;
            display: flex;
            align-items: center;
            justify-content: center;
            position: relative;
            overflow: hidden;
        }

        .ztdk-feature-text {
            flex: 1;
            min-width: 320px;
        }

        .ztdk-feature-label {
            color: var(--ztdk-primary);
            font-weight: 700;
            margin-bottom: 16px;
            display: block;
        }

        .ztdk-feature-h {
            font-size: 2.2rem;
            margin-bottom: 24px;
            line-height: 1.3;
        }

        /* 技术架构区块 */
        .ztdk-tech-layers {
            padding: 96px 0;
            background: #202124;
            color: var(--ztdk-white);
        }

        .ztdk-layer-card {
            border-left: 4px solid var(--ztdk-primary);
            padding: 32px;
            background: rgba(255,255,255,0.03);
            margin-bottom: 24px;
            border-radius: 0 16px 16px 0;
            transition: var(--ztdk-transition);
        }

        .ztdk-layer-card:hover {
            background: rgba(255,255,255,0.06);
            transform: translateX(10px);
        }

        /* 页脚 */
        .ztdk-footer {
            background: var(--ztdk-bg-gray);
            padding: 80px 0 40px;
            border-top: 1px solid rgba(0,0,0,0.05);
        }

        .ztdk-footer-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
            gap: 48px;
            margin-bottom: 64px;
        }

        .ztdk-footer-brand {
            font-size: 1.5rem;
            font-weight: 700;
            margin-bottom: 24px;
            color: var(--ztdk-text-dark);
        }

        .ztdk-footer-links {
            list-style: none;
        }

        .ztdk-footer-link {
            display: block;
            margin-bottom: 12px;
            color: var(--ztdk-text-light);
            text-decoration: none;
            transition: var(--ztdk-transition);
        }

        .ztdk-footer-link:hover {
            color: var(--ztdk-primary);
        }

        .ztdk-bottom-bar {
            padding-top: 40px;
            border-top: 1px solid rgba(0,0,0,0.05);
            display: flex;
            flex-wrap: wrap;
            justify-content: space-between;
            align-items: center;
            gap: 24px;
            color: var(--ztdk-text-light);
            font-size: 0.9rem;
        }

        /* 响应式调整 */
        @media (max-width: 1024px) {
            .ztdk-container-wide { padding: 0 24px; }
            .ztdk-hero-title { font-size: 3rem; }
        }

        @media (max-width: 768px) {
            .ztdk-nav-menu { display: none; } /* 移动端建议隐藏或使用汉堡菜单，此处简化 */
            .ztdk-hero { padding-top: 100px; text-align: center; }
            .ztdk-hero-subtitle { margin: 0 auto 40px; }
            .ztdk-hero-visual { order: -1; }
            .ztdk-sync-box { height: 300px; transform: none; }
            .ztdk-feature-split { flex-direction: column !important; text-align: center; }
            .ztdk-feature-image { width: 100%; height: 300px; }
        }