: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: #ffffff;
            --ztdk-bg-soft: #f8f9fa;
            --ztdk-spacing-unit: 8px;
            --ztdk-border-radius: 16px;
            --ztdk-transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
        }

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

        body {
            font-family: "Segoe UI", Roboto, Helvetica, Arial, "PingFang SC", "Microsoft YaHei", sans-serif;
            color: var(--ztdk-text-main);
            line-height: 1.6;
            background-color: var(--ztdk-bg-light);
            overflow-x: hidden;
            word-break: break-word;
        }

        /* 导航栏设计：动态光迹效果 */
        .ztdk-navbar {
            position: fixed;
            top: 0;
            left: 0;
            right: 0;
            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 5vw;
        }

        .ztdk-nav-container {
            max-width: 1400px;
            margin: 0 auto;
            display: flex;
            flex-wrap: wrap;
            justify-content: space-between;
            align-items: center;
            height: 80px;
        }

        .ztdk-logo {
            flex: 0 0 auto;
            min-width: 0;
        }

        .ztdk-logo img {
            height: 32px;
            display: block;
        }

        .ztdk-nav-menu {
            display: flex;
            flex-wrap: wrap;
            list-style: none;
            gap: calc(var(--ztdk-spacing-unit) * 3);
        }

        .ztdk-nav-item a {
            text-decoration: none;
            color: var(--ztdk-text-sub);
            font-size: 0.95rem;
            font-weight: 500;
            position: relative;
            padding: 8px 0;
            transition: var(--ztdk-transition);
        }

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

        /* 动态光迹悬停效果 */
        .ztdk-nav-item a::after {
            content: '';
            position: absolute;
            bottom: 0;
            left: 0;
            width: 0;
            height: 2px;
            background: linear-gradient(90deg, var(--ztdk-google-blue), var(--ztdk-google-green), var(--ztdk-google-yellow), var(--ztdk-google-red));
            transition: width 0.4s ease;
        }

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

        /* Hero 区：对角线分割设计 */
        .ztdk-hero {
            padding: 160px 5vw 100px;
            background: radial-gradient(circle at 90% 10%, rgba(66, 133, 244, 0.05) 0%, transparent 40%),
                        radial-gradient(circle at 10% 90%, rgba(52, 168, 83, 0.05) 0%, transparent 40%);
            display: flex;
            flex-wrap: wrap;
            align-items: center;
            max-width: 1400px;
            margin: 0 auto;
        }

        .ztdk-hero-content {
            flex: 1 1 500px;
            min-width: 0;
            padding-right: 48px;
        }

        .ztdk-hero-title {
            font-size: clamp(2.5rem, 5vw, 4rem);
            line-height: 1.1;
            font-weight: 700;
            margin-bottom: 24px;
            background: linear-gradient(135deg, #1a73e8 0%, #174ea6 100%);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
        }

        .ztdk-hero-subtitle {
            font-size: clamp(1.1rem, 2vw, 1.4rem);
            color: var(--ztdk-text-sub);
            margin-bottom: 40px;
            max-width: 600px;
        }

        .ztdk-hero-visual {
            flex: 1 1 400px;
            min-width: 0;
            position: relative;
        }

        .ztdk-keyboard-master {
            background: #fff;
            border-radius: var(--ztdk-border-radius);
            box-shadow: 0 20px 50px rgba(0,0,0,0.1);
            padding: 32px;
            border: 1px solid rgba(0,0,0,0.05);
            transform: perspective(1000px) rotateY(-5deg);
        }

        /* 快捷键卡片网格 */
        .ztdk-section {
            padding: 80px 5vw;
            max-width: 1400px;
            margin: 0 auto;
        }

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

        .ztdk-grid-shortcuts {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
            gap: 24px;
        }

        .ztdk-shortcut-card {
            background: var(--ztdk-bg-soft);
            padding: 32px;
            border-radius: var(--ztdk-border-radius);
            transition: var(--ztdk-transition);
            border: 1px solid transparent;
            display: flex;
            flex-direction: column;
        }

        .ztdk-shortcut-card:hover {
            transform: translateY(-8px);
            background: #fff;
            box-shadow: 0 12px 30px rgba(0,0,0,0.08);
            border-color: var(--ztdk-google-blue);
        }

        .ztdk-card-icon {
            font-size: 2rem;
            margin-bottom: 16px;
        }

        .ztdk-card-title {
            font-size: 1.5rem;
            margin-bottom: 16px;
            color: var(--ztdk-google-blue);
        }

        .ztdk-shortcut-list {
            list-style: none;
        }

        .ztdk-shortcut-item {
            display: flex;
            justify-content: space-between;
            padding: 12px 0;
            border-bottom: 1px solid rgba(0,0,0,0.05);
        }

        .ztdk-kbd {
            background: #e8eaed;
            padding: 2px 8px;
            border-radius: 4px;
            font-family: monospace;
            font-weight: bold;
            font-size: 0.9rem;
        }

        /* 核心架构层设计 */
        .ztdk-tech-layers {
            background: #202124;
            color: #fff;
            border-radius: 24px;
            padding: 64px;
            margin: 40px 0;
        }

        .ztdk-layer-item {
            display: flex;
            flex-wrap: wrap;
            gap: 32px;
            margin-bottom: 48px;
            align-items: center;
        }

        .ztdk-layer-info {
            flex: 1 1 300px;
            min-width: 0;
        }

        .ztdk-layer-badge {
            display: inline-block;
            padding: 4px 12px;
            background: var(--ztdk-google-blue);
            border-radius: 20px;
            font-size: 0.8rem;
            margin-bottom: 16px;
        }

        /* 响应式设计 */
        @media (max-width: 768px) {
            .ztdk-nav-container {
                height: auto;
                padding: 16px 0;
            }
            .ztdk-nav-menu {
                display: none; /* 简化演示：移动端可折叠 */
            }
            .ztdk-hero {
                padding-top: 120px;
                text-align: center;
            }
            .ztdk-hero-content {
                padding-right: 0;
            }
            .ztdk-hero-visual {
                display: none;
            }
            .ztdk-tech-layers {
                padding: 32px;
            }
        }

        .ztdk-btn {
            display: inline-block;
            padding: 16px 32px;
            border-radius: 30px;
            text-decoration: none;
            font-weight: 600;
            transition: var(--ztdk-transition);
            cursor: pointer;
            border: none;
        }

        .ztdk-btn-primary {
            background: var(--ztdk-google-blue);
            color: #fff;
        }

        .ztdk-btn-primary:hover {
            background: #174ea6;
            box-shadow: 0 4px 15px rgba(66, 133, 244, 0.3);
        }

        .ztdk-footer {
            background: var(--ztdk-bg-soft);
            padding: 64px 5vw;
            border-top: 1px solid rgba(0,0,0,0.05);
        }

        .ztdk-footer-content {
            max-width: 1400px;
            margin: 0 auto;
            display: flex;
            flex-wrap: wrap;
            justify-content: space-between;
            gap: 40px;
        }

        .ztdk-footer-brand {
            flex: 1 1 300px;
            min-width: 0;
        }

        .ztdk-brand-name {
            font-size: 1.5rem;
            font-weight: 700;
            margin-bottom: 16px;
        }