/* 基础变量与重置 */
        :root {
            --ztdk-google-blue: #4285F4;
            --ztdk-google-red: #EA4335;
            --ztdk-google-yellow: #FBBC05;
            --ztdk-google-green: #34A853;
            --ztdk-text-main: #202124;
            --ztdk-text-sub: #5f6368;
            --ztdk-bg-light: #f8f9fa;
            --ztdk-white: #ffffff;
            --ztdk-spacing-unit: 8px;
            --ztdk-container-max: 1100px;
            --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", "Microsoft YaHei", Roboto, Helvetica, Arial, sans-serif;
            color: var(--ztdk-text-main);
            background-color: var(--ztdk-white);
            line-height: 1.6;
            overflow-x: hidden;
            word-break: break-word;
        }

        /* 排版系统 */
        h1, h2, h3, h4 {
            line-height: 1.2;
            margin-bottom: calc(var(--ztdk-spacing-unit) * 2);
            white-space: normal;
            font-weight: 700;
        }

        h1 { font-size: clamp(2.2rem, 5vw + 1rem, 3.8rem); }
        h2 { font-size: clamp(1.8rem, 3vw + 0.8rem, 2.5rem); }
        h3 { font-size: clamp(1.3rem, 2vw + 0.5rem, 1.8rem); }
        p { font-size: clamp(1rem, 1vw + 0.5rem, 1.125rem); line-height: 1.8; margin-bottom: 1rem; }

        /* 导航菜单 - 动态光迹效果 */
        .ztdk-navbar {
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            z-index: 1000;
            background: rgba(255, 255, 255, 0.9);
            backdrop-filter: blur(10px);
            border-bottom: 1px solid rgba(0,0,0,0.05);
            padding: 0 calc(var(--ztdk-spacing-unit) * 2);
        }

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

        .ztdk-logo {
            flex-shrink: 0;
            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: calc(var(--ztdk-spacing-unit) * 2);
            min-width: 0;
        }

        .ztdk-nav-link {
            text-decoration: none;
            color: var(--ztdk-text-sub);
            font-size: 0.95rem;
            font-weight: 500;
            position: relative;
            padding: 8px 4px;
            transition: var(--ztdk-transition);
        }

        /* 动态光迹悬停效果 */
        .ztdk-nav-link::after {
            content: '';
            position: absolute;
            bottom: 0;
            left: 50%;
            width: 0;
            height: 3px;
            background: linear-gradient(90deg, var(--ztdk-google-blue), var(--ztdk-google-red), var(--ztdk-google-yellow), var(--ztdk-google-green));
            transition: var(--ztdk-transition);
            transform: translateX(-50%);
            border-radius: 2px;
        }

        .ztdk-nav-link:hover::after,
        .ztdk-nav-link.ztdk-active::after {
            width: 100%;
        }

        .ztdk-nav-link:hover,
        .ztdk-nav-link.ztdk-active {
            color: var(--ztdk-google-blue);
        }

        /* Hero 区 - 卡片浮动布局 */
        .ztdk-hero {
            padding: 160px 24px 80px;
            background: radial-gradient(circle at 90% 10%, rgba(66, 133, 244, 0.05) 0%, rgba(255,255,255,1) 50%);
            position: relative;
            overflow: hidden;
        }

        .ztdk-hero-wrapper {
            max-width: var(--ztdk-container-max);
            margin: 0 auto;
            display: flex;
            flex-wrap: wrap;
            align-items: center;
            gap: 48px;
        }

        .ztdk-hero-content {
            flex: 1;
            min-width: 320px;
        }

        .ztdk-hero-visual {
            flex: 1;
            min-width: 320px;
            position: relative;
        }

        .ztdk-hero-image-card {
            background: var(--ztdk-white);
            border-radius: 24px;
            box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.1);
            padding: 16px;
            transform: rotate(2deg);
            transition: var(--ztdk-transition);
        }

        .ztdk-hero-image-card:hover {
            transform: rotate(0deg) translateY(-10px);
        }

        .ztdk-hero-image-card img {
            width: 100%;
            height: auto;
            border-radius: 16px;
            display: block;
        }

        .ztdk-badge {
            display: inline-block;
            padding: 6px 16px;
            background: rgba(66, 133, 244, 0.1);
            color: var(--ztdk-google-blue);
            border-radius: 100px;
            font-weight: 600;
            margin-bottom: 24px;
            font-size: 0.875rem;
        }

        .ztdk-btn-group {
            display: flex;
            flex-wrap: wrap;
            gap: 16px;
            margin-top: 32px;
        }

        .ztdk-btn {
            display: inline-block;
            padding: 16px 36px;
            border-radius: 12px;
            text-decoration: none;
            font-weight: 600;
            transition: var(--ztdk-transition);
            cursor: pointer;
            text-align: center;
            min-width: 180px;
        }

        .ztdk-btn-primary {
            background: var(--ztdk-google-blue);
            color: var(--ztdk-white);
            box-shadow: 0 4px 14px 0 rgba(66, 133, 244, 0.39);
        }

        .ztdk-btn-primary:hover {
            background: #3367d6;
            transform: translateY(-2px);
            box-shadow: 0 6px 20px rgba(66, 133, 244, 0.23);
        }

        .ztdk-btn-outline {
            border: 2px solid #dadce0;
            color: var(--ztdk-text-main);
        }

        .ztdk-btn-outline:hover {
            background: #f1f3f4;
            border-color: #bdc1c6;
        }

        /* 核心技术区块 - 杂志化排版 */
        .ztdk-tech-section {
            padding: 96px 24px;
            background-color: var(--ztdk-bg-light);
        }

        .ztdk-section-header {
            max-width: 800px;
            margin: 0 auto 64px;
            text-align: center;
        }

        .ztdk-grid-asymmetric {
            max-width: var(--ztdk-container-max);
            margin: 0 auto;
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
            gap: 32px;
        }

        .ztdk-tech-card {
            background: var(--ztdk-white);
            padding: 40px;
            border-radius: 20px;
            border: 1px solid rgba(0,0,0,0.03);
            transition: var(--ztdk-transition);
            display: flex;
            flex-direction: column;
            min-width: 0;
        }

        .ztdk-tech-card:hover {
            box-shadow: 0 20px 40px rgba(0,0,0,0.05);
            border-color: var(--ztdk-google-blue);
        }

        .ztdk-tech-icon {
            width: 48px;
            height: 48px;
            border-radius: 12px;
            display: flex;
            align-items: center;
            justify-content: center;
            margin-bottom: 24px;
            font-size: 1.5rem;
            font-weight: bold;
        }

        .ztdk-tech-card:nth-child(1) .ztdk-tech-icon { background: rgba(66, 133, 244, 0.1); color: var(--ztdk-google-blue); }
        .ztdk-tech-card:nth-child(2) .ztdk-tech-icon { background: rgba(52, 168, 83, 0.1); color: var(--ztdk-google-green); }
        .ztdk-tech-card:nth-child(3) .ztdk-tech-icon { background: rgba(251, 188, 5, 0.1); color: var(--ztdk-google-yellow); }

        .ztdk-tech-tag {
            display: inline-block;
            margin: 4px;
            padding: 4px 12px;
            background: #f1f3f4;
            border-radius: 6px;
            font-size: 0.8rem;
            color: var(--ztdk-text-sub);
        }

        /* 隐私与安全展示 - 图文交叉 */
        .ztdk-privacy-section {
            padding: 96px 24px;
        }

        .ztdk-split-row {
            max-width: var(--ztdk-container-max);
            margin: 0 auto 80px;
            display: flex;
            flex-wrap: wrap;
            align-items: center;
            gap: 64px;
        }

        .ztdk-split-row:nth-child(even) {
            flex-direction: row-reverse;
        }

        .ztdk-split-text {
            flex: 1;
            min-width: 300px;
        }

        .ztdk-split-visual {
            flex: 1.2;
            min-width: 320px;
        }

        .ztdk-split-visual img {
            width: 100%;
            height: auto;
            border-radius: 32px;
            box-shadow: 0 10px 30px rgba(0,0,0,0.08);
            display: block;
        }

        /* 数据矩阵区块 */
        .ztdk-matrix-section {
            padding: 80px 24px;
            background: linear-gradient(135deg, #202124 0%, #3c4043 100%);
            color: var(--ztdk-white);
        }

        .ztdk-matrix-container {
            max-width: var(--ztdk-container-max);
            margin: 0 auto;
        }

        .ztdk-matrix-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
            gap: 24px;
        }

        .ztdk-matrix-item {
            padding: 32px;
            background: rgba(255,255,255,0.05);
            border-radius: 16px;
            backdrop-filter: blur(5px);
            border: 1px solid rgba(255,255,255,0.1);
        }

        .ztdk-matrix-label {
            color: var(--ztdk-google-blue);
            font-weight: 700;
            text-transform: uppercase;
            letter-spacing: 1px;
            font-size: 0.8rem;
            margin-bottom: 12px;
            display: block;
        }

        /* 下载版本表格 */
        .ztdk-download-table-section {
            padding: 96px 24px;
        }

        .ztdk-table-wrapper {
            max-width: var(--ztdk-container-max);
            margin: 0 auto;
            overflow-x: auto;
            background: var(--ztdk-white);
            border-radius: 20px;
            box-shadow: 0 4px 20px rgba(0,0,0,0.05);
        }

        table {
            width: 100%;
            border-collapse: collapse;
            min-width: 600px;
        }

        th, td {
            padding: 24px;
            text-align: left;
            border-bottom: 1px solid #f1f3f4;
        }

        th {
            background: #f8f9fa;
            color: var(--ztdk-text-sub);
            font-weight: 600;
        }

        /* 底部动态内容 */
        .ztdk-dynamic-news {
            padding: 80px 24px;
            background: var(--ztdk-bg-light);
        }

        .ztdk-news-grid {
            max-width: var(--ztdk-container-max);
            margin: 0 auto;
            display: flex;
            flex-wrap: wrap;
            gap: 24px;
        }

        .ztdk-news-card {
            flex: 1;
            min-width: 300px;
            background: var(--ztdk-white);
            padding: 24px;
            border-radius: 12px;
            text-decoration: none;
            color: inherit;
            transition: var(--ztdk-transition);
        }

        .ztdk-news-card:hover {
            transform: translateY(-5px);
            box-shadow: 0 10px 20px rgba(0,0,0,0.05);
        }

        /* 页脚 */
        .ztdk-footer {
            padding: 80px 24px 40px;
            background: var(--ztdk-white);
            border-top: 1px solid #f1f3f4;
        }

        .ztdk-footer-container {
            max-width: var(--ztdk-container-max);
            margin: 0 auto;
            display: flex;
            flex-wrap: wrap;
            justify-content: space-between;
            gap: 48px;
        }

        .ztdk-footer-brand {
            flex: 1;
            min-width: 240px;
        }

        .ztdk-footer-brand-name {
            font-size: 1.5rem;
            font-weight: 700;
            color: var(--ztdk-text-main);
            margin-bottom: 16px;
        }

        .ztdk-footer-links {
            flex: 2;
            display: flex;
            flex-wrap: wrap;
            gap: 40px;
        }

        .ztdk-footer-col {
            min-width: 140px;
        }

        .ztdk-footer-col h4 {
            font-size: 0.9rem;
            color: var(--ztdk-text-sub);
            margin-bottom: 24px;
        }

        .ztdk-footer-col ul {
            list-style: none;
        }

        .ztdk-footer-col li {
            margin-bottom: 12px;
        }

        .ztdk-footer-col a {
            text-decoration: none;
            color: var(--ztdk-text-main);
            font-size: 0.9rem;
            transition: color 0.2s;
        }

        .ztdk-footer-col a:hover {
            color: var(--ztdk-google-blue);
        }

        .ztdk-footer-bottom {
            max-width: var(--ztdk-container-max);
            margin: 64px auto 0;
            padding-top: 32px;
            border-top: 1px solid #f1f3f4;
            display: flex;
            flex-wrap: wrap;
            justify-content: space-between;
            align-items: center;
            color: var(--ztdk-text-sub);
            font-size: 0.85rem;
        }

        /* 响应式调整 */
        @media (max-width: 768px) {
            .ztdk-nav-container { height: auto; padding: 16px 0; }
            .ztdk-nav-menu { display: none; } /* 移动端通常配合汉堡菜单，此处简化 */
            .ztdk-hero { padding-top: 120px; }
            .ztdk-split-row { gap: 32px; }
            .ztdk-tech-card { padding: 24px; }
        }