:root {
            --r6tl-primary: #FF6C37; /* Postman Orange */
            --r6tl-accent: #00F2FE;
            --r6tl-bg-dark: #1C2733;
            --r6tl-bg-light: #F8F9FA;
            --r6tl-text-main: #212121;
            --r6tl-text-muted: #6B6B6B;
            --r6tl-white: #ffffff;
            --r6tl-glass: rgba(255, 255, 255, 0.8);
            --r6tl-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
            --r6tl-container-max: 1300px;
        }

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

        body {
            font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
            color: var(--r6tl-text-main);
            line-height: 1.6;
            background-color: var(--r6tl-white);
            word-break: keep-all;
            overflow-x: hidden;
        }

        /* 导航系统 */
        .r6tl-header {
            position: sticky;
            top: 0;
            z-index: 1000;
            background: var(--r6tl-glass);
            backdrop-filter: blur(10px);
            border-bottom: 1px solid rgba(0,0,0,0.05);
            box-shadow: var(--r6tl-shadow);
        }

        .r6tl-nav-container {
            max-width: var(--r6tl-container-max);
            margin: 0 auto;
            display: flex;
            flex-wrap: wrap;
            align-items: center;
            justify-content: space-between;
            padding: 16px 24px;
        }

        .r6tl-logo {
            flex: 0 0 auto;
            min-width: 0;
        }

        .r6tl-logo img {
            height: 32px;
            display: block;
        }

        .r6tl-nav-menu {
            display: flex;
            flex-wrap: wrap;
            list-style: none;
            gap: 12px;
            min-width: 0;
        }

        .r6tl-nav-item a {
            text-decoration: none;
            color: var(--r6tl-text-main);
            font-size: 14px;
            font-weight: 500;
            padding: 8px 12px;
            border-radius: 6px;
            transition: all 0.3s ease;
            white-space: nowrap;
        }

        .r6tl-nav-item a:hover {
            color: var(--r6tl-primary);
            background: rgba(255, 108, 55, 0.05);
        }

        .r6tl-nav-item a.active {
            color: var(--r6tl-white);
            background: var(--r6tl-primary);
        }

        /* Hero 视觉区 - 独特全屏渐变风格 */
        .r6tl-hero {
            position: relative;
            padding: 96px 24px;
            background: radial-gradient(circle at top right, #fff5f2, #ffffff);
            overflow: hidden;
            text-align: center;
        }

        .r6tl-hero-inner {
            max-width: 900px;
            margin: 0 auto;
            position: relative;
            z-index: 2;
        }

        .r6tl-badge {
            display: inline-block;
            background: rgba(0, 242, 254, 0.1);
            color: #008c94;
            padding: 6px 16px;
            border-radius: 50px;
            font-size: 14px;
            font-weight: 600;
            margin-bottom: 24px;
        }

        .r6tl-hero-title {
            font-size: clamp(2rem, 5vw + 1rem, 4rem);
            line-height: 1.1;
            font-weight: 800;
            color: var(--r6tl-bg-dark);
            margin-bottom: 24px;
            word-break: break-word;
        }

        .r6tl-hero-subtitle {
            font-size: clamp(1rem, 2vw + 0.5rem, 1.25rem);
            color: var(--r6tl-text-muted);
            max-width: 700px;
            margin: 0 auto 48px;
            word-break: break-word;
        }

        /* 核心教程阶段 - 矩阵布局 */
        .r6tl-section {
            padding: 80px 24px;
            max-width: var(--r6tl-container-max);
            margin: 0 auto;
        }

        .r6tl-matrix-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
            gap: 32px;
            margin-top: 48px;
        }

        .r6tl-matrix-card {
            background: var(--r6tl-white);
            border: 1px solid rgba(0,0,0,0.06);
            border-radius: 20px;
            padding: 40px;
            transition: transform 0.3s ease, box-shadow 0.3s ease;
            display: flex;
            flex-direction: column;
            min-width: 0;
        }

        .r6tl-matrix-card:hover {
            transform: translateY(-8px);
            box-shadow: 0 20px 40px rgba(255, 108, 55, 0.1);
            border-color: var(--r6tl-primary);
        }

        .r6tl-card-stage {
            font-size: 12px;
            text-transform: uppercase;
            letter-spacing: 2px;
            color: var(--r6tl-primary);
            font-weight: 700;
            margin-bottom: 12px;
        }

        .r6tl-card-title {
            font-size: 24px;
            margin-bottom: 16px;
            color: var(--r6tl-bg-dark);
        }

        .r6tl-card-method {
            font-style: italic;
            color: var(--r6tl-text-muted);
            margin-bottom: 24px;
            padding-bottom: 24px;
            border-bottom: 1px dashed #eee;
        }

        .r6tl-tool-item {
            margin-bottom: 16px;
        }

        .r6tl-tool-label {
            display: block;
            font-weight: 600;
            font-size: 14px;
            color: var(--r6tl-bg-dark);
            margin-bottom: 4px;
        }

        .r6tl-tool-desc {
            font-size: 14px;
            color: var(--r6tl-text-muted);
            word-break: break-word;
        }

        /* 教程主体区 */
        .r6tl-tutorial-content {
            background: var(--r6tl-bg-light);
            border-radius: 32px;
            padding: 64px;
            margin-top: 64px;
        }

        .r6tl-step-list {
            display: flex;
            flex-wrap: wrap;
            gap: 48px;
        }

        .r6tl-step-item {
            flex: 1 1 400px;
            min-width: 0;
        }

        .r6tl-step-num {
            font-size: 48px;
            font-weight: 900;
            color: rgba(255, 108, 55, 0.1);
            line-height: 1;
            margin-bottom: -20px;
            position: relative;
            z-index: 1;
        }

        .r6tl-step-box {
            background: var(--r6tl-white);
            padding: 32px;
            border-radius: 16px;
            position: relative;
            z-index: 2;
            box-shadow: 0 4px 12px rgba(0,0,0,0.03);
        }

        /* 动态资讯区标记 */
        .r6tl-news-section {
            background: var(--r6tl-bg-dark);
            color: var(--r6tl-white);
            border-radius: 0;
            padding: 96px 24px;
            margin-top: 64px;
            width: 100vw;
            margin-left: calc(50% - 50vw);
        }

        .r6tl-news-container {
            max-width: var(--r6tl-container-max);
            margin: 0 auto;
        }

        /* 页脚 */
        .r6tl-footer {
            padding: 64px 24px;
            border-top: 1px solid #eee;
            background: #fff;
        }

        .r6tl-footer-grid {
            max-width: var(--r6tl-container-max);
            margin: 0 auto;
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
            gap: 48px;
        }

        .r6tl-footer-brand {
            font-size: 24px;
            font-weight: 800;
            color: var(--r6tl-primary);
            margin-bottom: 16px;
        }

        .r6tl-footer-link {
            display: block;
            text-decoration: none;
            color: var(--r6tl-text-muted);
            margin-bottom: 12px;
            font-size: 14px;
            transition: color 0.3s;
        }

        .r6tl-footer-link:hover {
            color: var(--r6tl-primary);
        }

        /* 响应式适配 */
        @media (max-width: 768px) {
            .r6tl-nav-menu {
                display: none; /* 简化演示：移动端通常使用汉堡菜单 */
            }
            .r6tl-matrix-grid {
                grid-template-columns: 1fr;
            }
            .r6tl-tutorial-content {
                padding: 32px 20px;
            }
            .r6tl-hero {
                padding: 64px 20px;
            }
        }

        /* 装饰元素 */
        .r6tl-decor-circle {
            position: absolute;
            width: 400px;
            height: 400px;
            border-radius: 50%;
            background: linear-gradient(135deg, rgba(255,108,55,0.05) 0%, rgba(0,242,254,0.05) 100%);
            z-index: 1;
            top: -100px;
            right: -100px;
        }