/* roulang page: index */
:root {
      --bg-main: #0B0D11;
      --bg-card: #161920;
      --bg-card-hover: #1D212B;
      --border-color: #222733;
      --border-light: rgba(255, 255, 255, 0.08);
      --accent-cyan: #00F5D4;
      --accent-purple: #7928CA;
      --text-white: #F0F4F8;
      --text-muted: #9BA3AF;
      --text-dim: #8F9CA9;
      --radius-sm: 6px;
      --radius-md: 10px;
      --radius-lg: 16px;
      --transition-smooth: all 240ms cubic-bezier(0.16, 1, 0.3, 1);
      --container-max: 1280px;
      --font-code: "JetBrains Mono", Menlo, Consolas, monospace;
    }

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

    body {
      background-color: var(--bg-main);
      color: var(--text-white);
      font-family: system-ui, -apple-system, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
      line-height: 1.65;
      font-size: 15px;
      -webkit-font-smoothing: antialiased;
      overflow-x: hidden;
    }

    a {
      color: inherit;
      text-decoration: none;
      transition: var(--transition-smooth);
    }

    img {
      max-width: 100%;
      height: auto;
      display: block;
    }

    .container {
      width: 100%;
      max-width: var(--container-max);
      margin: 0 auto;
      padding: 0 24px;
    }

    /* 顶部双行导航系统 */
    .top-statusbar {
      background: #060709;
      border-bottom: 1px solid var(--border-color);
      font-size: 12px;
      color: var(--text-dim);
      padding: 6px 0;
    }
    .top-statusbar-inner {
      display: flex;
      justify-content: space-between;
      align-items: center;
    }
    .status-badge {
      display: inline-flex;
      align-items: center;
      gap: 6px;
    }
    .status-dot {
      width: 7px;
      height: 7px;
      background: var(--accent-cyan);
      border-radius: 50%;
      box-shadow: 0 0 8px var(--accent-cyan);
    }

    header.site-header {
      position: sticky;
      top: 0;
      z-index: 1000;
      background: rgba(11, 13, 17, 0.95);
      backdrop-filter: blur(12px);
      border-bottom: 1px solid var(--border-light);
    }
    .header-nav {
      display: flex;
      justify-content: space-between;
      align-items: center;
      height: 70px;
    }
    .brand-logo {
      display: flex;
      align-items: center;
      gap: 10px;
      font-size: 19px;
      font-weight: 800;
      letter-spacing: -0.5px;
      color: var(--text-white);
    }
    .brand-logo-icon {
      width: 32px;
      height: 32px;
      background: linear-gradient(135deg, var(--accent-cyan), var(--accent-purple));
      border-radius: var(--radius-sm);
      display: flex;
      align-items: center;
      justify-content: center;
      color: #000;
      font-weight: 900;
      font-size: 16px;
    }
    .nav-links {
      display: flex;
      gap: 28px;
      list-style: none;
    }
    .nav-links a {
      color: var(--text-muted);
      font-size: 14px;
      font-weight: 500;
    }
    .nav-links a:hover {
      color: var(--accent-cyan);
    }
    .nav-actions {
      display: flex;
      align-items: center;
      gap: 16px;
    }
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      padding: 10px 22px;
      border-radius: var(--radius-sm);
      font-weight: 600;
      font-size: 14px;
      cursor: pointer;
      transition: var(--transition-smooth);
      border: 1px solid transparent;
      white-space: nowrap;
    }
    .btn-primary {
      background: var(--accent-cyan);
      color: #050608;
    }
    .btn-primary:hover {
      background: #00d9bc;
      box-shadow: 0 0 16px rgba(0, 245, 212, 0.4);
      transform: translateY(-1px);
    }
    .btn-outline {
      background: rgba(255, 255, 255, 0.03);
      color: var(--text-white);
      border-color: var(--border-light);
    }
    .btn-outline:hover {
      background: rgba(255, 255, 255, 0.08);
      border-color: var(--accent-cyan);
    }

    .mobile-toggle {
      display: none;
      background: none;
      border: 1px solid var(--border-color);
      color: var(--text-white);
      padding: 6px 10px;
      border-radius: 4px;
      cursor: pointer;
    }

    /* Section 通用规范 */
    section.page-section {
      padding: 96px 0;
      position: relative;
      border-bottom: 1px solid var(--border-color);
    }
    section.page-section.bg-alt {
      background-color: #0E1015;
    }
    section.page-section.bg-darker {
      background-color: #07080A;
    }
    .section-header {
      margin-bottom: 54px;
      max-width: 780px;
    }
    .section-header.center {
      margin-left: auto;
      margin-right: auto;
      text-align: center;
    }
    .section-tag {
      display: inline-block;
      font-size: 12px;
      text-transform: uppercase;
      font-family: var(--font-code);
      color: var(--accent-cyan);
      background: rgba(0, 245, 212, 0.08);
      padding: 4px 10px;
      border-radius: 4px;
      margin-bottom: 14px;
      border: 1px solid rgba(0, 245, 212, 0.2);
    }
    .section-title {
      font-size: 32px;
      font-weight: 800;
      letter-spacing: -0.5px;
      line-height: 1.25;
      margin-bottom: 16px;
      color: var(--text-white);
    }
    .section-desc {
      font-size: 15px;
      color: var(--text-muted);
      line-height: 1.7;
    }

    /* 卡片体系 */
    .card {
      background: var(--bg-card);
      border: 1px solid var(--border-light);
      border-radius: var(--radius-md);
      padding: 28px;
      transition: var(--transition-smooth);
    }
    .card:hover {
      background: var(--bg-card-hover);
      border-color: rgba(0, 245, 212, 0.3);
      transform: translateY(-3px);
    }

    /* 板块 1: Hero (banner) */
    #banner {
      position: relative;
      padding: 100px 0 80px;
      background: radial-gradient(circle at 80% 20%, rgba(121, 40, 202, 0.18), transparent 45%),
                  radial-gradient(circle at 20% 80%, rgba(0, 245, 212, 0.12), transparent 40%),
                  var(--bg-main);
      overflow: hidden;
    }
    .hero-grid {
      display: grid;
      grid-template-columns: 1.15fr 0.85fr;
      gap: 48px;
      align-items: center;
    }
    .hero-content h1 {
      font-size: 42px;
      font-weight: 800;
      line-height: 1.2;
      margin-bottom: 20px;
      letter-spacing: -1px;
    }
    .hero-content h1 span.gradient-text {
      background: linear-gradient(90deg, #FFFFFF 0%, var(--accent-cyan) 100%);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
    }
    .hero-content p.hero-lead {
      font-size: 16px;
      color: var(--text-muted);
      line-height: 1.75;
      margin-bottom: 32px;
    }
    .hero-actions {
      display: flex;
      gap: 16px;
      margin-bottom: 40px;
      flex-wrap: wrap;
    }
    .hero-stats-strip {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 20px;
      border-top: 1px solid var(--border-color);
      padding-top: 24px;
    }
    .hero-stat-item .val {
      font-family: var(--font-code);
      font-size: 24px;
      font-weight: 700;
      color: var(--text-white);
    }
    .hero-stat-item .lbl {
      font-size: 13px;
      color: var(--text-dim);
      margin-top: 2px;
    }
    .hero-console {
      background: #11141B;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-lg);
      padding: 24px;
      position: relative;
      box-shadow: 0 20px 50px rgba(0,0,0,0.5);
    }
    .console-header {
      display: flex;
      justify-content: space-between;
      align-items: center;
      padding-bottom: 14px;
      border-bottom: 1px solid var(--border-light);
      margin-bottom: 18px;
      font-size: 13px;
      color: var(--text-dim);
      font-family: var(--font-code);
    }
    .hero-preview-img {
      width: 100%;
      height: 240px;
      object-fit: cover;
      border-radius: var(--radius-sm);
      margin-bottom: 18px;
      border: 1px solid var(--border-color);
    }
    .telemetry-row {
      display: flex;
      justify-content: space-between;
      font-family: var(--font-code);
      font-size: 12px;
      color: var(--accent-cyan);
      margin-top: 8px;
    }

    /* 板块 2: 底层架构 (about-engine) */
    .arch-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 50px;
      align-items: center;
    }
    .arch-visual {
      position: relative;
    }
    .arch-visual img {
      border-radius: var(--radius-md);
      border: 1px solid var(--border-light);
    }
    .spec-table {
      width: 100%;
      margin-top: 24px;
      border-collapse: collapse;
      font-size: 14px;
    }
    .spec-table td {
      padding: 12px 14px;
      border-bottom: 1px solid var(--border-color);
    }
    .spec-table td.label {
      color: var(--text-dim);
      width: 38%;
      font-family: var(--font-code);
      font-size: 13px;
    }
    .spec-table td.value {
      color: var(--text-white);
      font-weight: 500;
    }

    /* 板块 3: 核心优势 (features) */
    .features-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .feature-card .feat-icon {
      width: 44px;
      height: 44px;
      border-radius: 8px;
      background: rgba(0, 245, 212, 0.1);
      display: flex;
      align-items: center;
      justify-content: center;
      margin-bottom: 18px;
      color: var(--accent-cyan);
      font-family: var(--font-code);
      font-weight: 700;
    }
    .feature-card h3 {
      font-size: 18px;
      font-weight: 700;
      margin-bottom: 10px;
      color: var(--text-white);
    }
    .feature-card p {
      font-size: 14px;
      color: var(--text-muted);
      line-height: 1.65;
    }

    /* 板块 4: 产品套件 (products) */
    .pricing-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
      align-items: stretch;
    }
    .product-card {
      display: flex;
      flex-direction: column;
      position: relative;
    }
    .product-card.featured {
      border-color: var(--accent-cyan);
      background: #181D26;
      box-shadow: 0 0 30px rgba(0, 245, 212, 0.12);
    }
    .featured-badge {
      position: absolute;
      top: -12px;
      right: 24px;
      background: var(--accent-cyan);
      color: #000;
      font-size: 11px;
      font-weight: 700;
      padding: 2px 10px;
      border-radius: 20px;
      text-transform: uppercase;
    }
    .product-card h3 {
      font-size: 20px;
      margin-bottom: 8px;
    }
    .product-desc {
      font-size: 14px;
      color: var(--text-muted);
      margin-bottom: 20px;
      min-height: 42px;
    }
    .product-param-list {
      list-style: none;
      margin-bottom: 30px;
      flex-grow: 1;
    }
    .product-param-list li {
      font-size: 13px;
      color: var(--text-white);
      padding: 8px 0;
      border-bottom: 1px solid rgba(255, 255, 255, 0.04);
      display: flex;
      align-items: center;
      gap: 8px;
    }
    .product-param-list li::before {
      content: "✓";
      color: var(--accent-cyan);
      font-weight: bold;
    }

    /* 板块 5: 渲染对比 (architecture) */
    .compare-container {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 30px;
    }
    .compare-col {
      padding: 32px;
      border-radius: var(--radius-md);
      border: 1px solid var(--border-light);
    }
    .compare-col.legacy {
      background: #121419;
      border-left: 4px solid #E5484D;
    }
    .compare-col.modern {
      background: #151A22;
      border-left: 4px solid var(--accent-cyan);
    }
    .compare-col h3 {
      font-size: 20px;
      margin-bottom: 16px;
    }
    .compare-list {
      list-style: none;
      font-size: 14px;
      color: var(--text-muted);
    }
    .compare-list li {
      padding: 10px 0;
      border-bottom: 1px solid rgba(255, 255, 255, 0.05);
      display: flex;
      justify-content: space-between;
    }
    .compare-list li span.val {
      font-family: var(--font-code);
      font-weight: 600;
      color: var(--text-white);
    }

    /* 板块 6: 性能看板 (metrics) */
    .metrics-strip {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 20px;
    }
    .metric-box {
      background: var(--bg-card);
      border: 1px solid var(--border-light);
      border-radius: var(--radius-md);
      padding: 28px 20px;
      text-align: center;
    }
    .metric-number {
      font-family: var(--font-code);
      font-size: 38px;
      font-weight: 800;
      color: var(--accent-cyan);
      line-height: 1.1;
      margin-bottom: 8px;
    }
    .metric-box h4 {
      font-size: 16px;
      margin-bottom: 6px;
      color: var(--text-white);
    }
    .metric-box p {
      font-size: 12px;
      color: var(--text-dim);
    }

    /* 板块 7: 技术里程碑 (milestones) */
    .timeline-wrap {
      position: relative;
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
      margin-top: 40px;
    }
    .timeline-wrap::before {
      content: "";
      position: absolute;
      top: 24px;
      left: 10%;
      right: 10%;
      height: 2px;
      background: var(--border-color);
      z-index: 1;
    }
    .timeline-item {
      position: relative;
      z-index: 2;
      background: var(--bg-card);
      border: 1px solid var(--border-light);
      border-radius: var(--radius-md);
      padding: 24px;
    }
    .timeline-node {
      width: 14px;
      height: 14px;
      background: var(--accent-cyan);
      border-radius: 50%;
      margin-bottom: 16px;
      box-shadow: 0 0 10px var(--accent-cyan);
    }
    .timeline-ver {
      font-family: var(--font-code);
      font-size: 13px;
      color: var(--accent-cyan);
      margin-bottom: 6px;
    }
    .timeline-item h4 {
      font-size: 16px;
      margin-bottom: 8px;
    }
    .timeline-item p {
      font-size: 13px;
      color: var(--text-muted);
      line-height: 1.6;
    }

    /* 板块 8: 开发服务 (services) */
    .services-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 20px;
    }
    .service-card {
      background: var(--bg-card);
      border: 1px solid var(--border-light);
      border-radius: var(--radius-md);
      padding: 26px;
    }
    .service-card h4 {
      font-size: 17px;
      margin-bottom: 10px;
      color: var(--text-white);
    }
    .service-card p {
      font-size: 13px;
      color: var(--text-muted);
      line-height: 1.6;
    }

    /* 板块 9: 实战案例 (stories) */
    .story-layout {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 40px;
      align-items: center;
      background: var(--bg-card);
      border: 1px solid var(--border-light);
      border-radius: var(--radius-lg);
      padding: 40px;
    }
    .story-img-col img {
      border-radius: var(--radius-md);
      border: 1px solid var(--border-color);
      width: 100%;
      height: 320px;
      object-fit: cover;
    }
    .story-content blockquote {
      font-size: 17px;
      font-style: italic;
      color: var(--text-white);
      line-height: 1.7;
      margin-bottom: 20px;
    }
    .story-author {
      font-size: 14px;
      color: var(--accent-cyan);
      font-weight: 600;
    }
    .story-stats {
      display: flex;
      gap: 24px;
      margin-top: 24px;
      border-top: 1px solid var(--border-color);
      padding-top: 18px;
    }
    .story-stat-val {
      font-family: var(--font-code);
      font-size: 20px;
      font-weight: 700;
      color: var(--text-white);
    }
    .story-stat-lbl {
      font-size: 12px;
      color: var(--text-dim);
    }

    /* 板块 10: 开发者评价 (testimonials) */
    .reviews-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .review-card {
      background: var(--bg-card);
      border: 1px solid var(--border-light);
      border-radius: var(--radius-md);
      padding: 28px;
      display: flex;
      flex-direction: column;
      justify-content: space-between;
    }
    .review-text {
      font-size: 14px;
      color: var(--text-muted);
      line-height: 1.7;
      margin-bottom: 20px;
    }
    .reviewer-meta {
      display: flex;
      align-items: center;
      gap: 12px;
    }
    .reviewer-avatar {
      width: 40px;
      height: 40px;
      border-radius: 50%;
      background: #252B38;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 700;
      color: var(--accent-cyan);
      font-size: 14px;
    }
    .reviewer-info h5 {
      font-size: 14px;
      color: var(--text-white);
    }
    .reviewer-info span {
      font-size: 12px;
      color: var(--text-dim);
    }

    /* 板块 11: 技术动态 (news) */
    .news-grid {
      display: grid;
      grid-template-columns: 1.2fr 0.8fr;
      gap: 24px;
    }
    .news-card-lead {
      background: var(--bg-card);
      border: 1px solid var(--border-light);
      border-radius: var(--radius-md);
      overflow: hidden;
      display: flex;
      flex-direction: column;
    }
    .news-card-lead img {
      width: 100%;
      height: 240px;
      object-fit: cover;
    }
    .news-card-lead-body {
      padding: 24px;
    }
    .news-sub-col {
      display: flex;
      flex-direction: column;
      gap: 20px;
    }
    .news-card-compact {
      background: var(--bg-card);
      border: 1px solid var(--border-light);
      border-radius: var(--radius-md);
      padding: 20px;
    }
    .news-date {
      font-family: var(--font-code);
      font-size: 12px;
      color: var(--accent-cyan);
      margin-bottom: 8px;
    }

    /* 板块 12: 平台保障 (guarantee) */
    .guarantee-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .guarantee-card {
      background: var(--bg-card);
      border: 1px solid var(--border-light);
      border-radius: var(--radius-md);
      padding: 30px;
    }
    .guarantee-card h4 {
      font-size: 18px;
      margin-bottom: 12px;
      color: var(--text-white);
      display: flex;
      align-items: center;
      gap: 10px;
    }
    .guarantee-card p {
      font-size: 14px;
      color: var(--text-muted);
      line-height: 1.65;
    }

    /* 板块 13: FAQ (faq) */
    .faq-wrapper {
      max-width: 860px;
      margin: 0 auto;
    }
    .faq-item {
      background: var(--bg-card);
      border: 1px solid var(--border-light);
      border-radius: var(--radius-sm);
      margin-bottom: 14px;
      overflow: hidden;
      transition: var(--transition-smooth);
    }
    .faq-item details summary {
      padding: 20px 24px;
      font-size: 16px;
      font-weight: 600;
      cursor: pointer;
      list-style: none;
      display: flex;
      justify-content: space-between;
      align-items: center;
      color: var(--text-white);
    }
    .faq-item details summary::-webkit-details-marker {
      display: none;
    }
    .faq-item details summary::after {
      content: "+";
      font-size: 20px;
      color: var(--accent-cyan);
      font-family: var(--font-code);
      transition: var(--transition-smooth);
    }
    .faq-item details[open] summary::after {
      transform: rotate(45deg);
    }
    .faq-content {
      padding: 0 24px 22px;
      font-size: 14px;
      color: var(--text-muted);
      line-height: 1.7;
    }

    /* 板块 14: CTA 行动表单 (cta) */
    .cta-container {    background: radial-gradient(circle at 10% 10%, rgba(0, 245, 212, 0.1), transparent 50%), #141822;
      border: 1px solid rgba(0, 245, 212, 0.3);
      border-radius: var(--radius-lg);
      padding: 50px 44px;
      display: grid;
      grid-template-columns: 1.1fr 0.9fr;
      gap: 40px;
      align-items: center;
      box-shadow: 0 20px 60px rgba(0, 0, 0, 0.6);
    }
    .cta-info h2 {
      font-size: 32px;
      font-weight: 800;
      line-height: 1.25;
      margin-bottom: 16px;
    }
    .cta-info p {
      font-size: 15px;
      color: var(--text-muted);
      line-height: 1.7;
      margin-bottom: 24px;
    }
    .cta-badges {
      display: flex;
      gap: 16px;
      font-size: 13px;
      color: var(--text-dim);
    }
    .cta-badges span {
      display: flex;
      align-items: center;
      gap: 6px;
    }
    .cta-form {
      display: flex;
      flex-direction: column;
      gap: 16px;
      background: #0B0D11;
      padding: 30px;
      border-radius: var(--radius-md);
      border: 1px solid var(--border-light);
    }
    .form-group {
      display: flex;
      flex-direction: column;
      gap: 6px;
    }
    .form-group label {
      font-size: 13px;
      font-weight: 500;
      color: var(--text-dim);
    }
    .form-input, .form-select {
      background: #161920;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-sm);
      padding: 12px 14px;
      color: var(--text-white);
      font-size: 14px;
      outline: none;
      transition: var(--transition-smooth);
    }
    .form-input:focus, .form-select:focus {
      border-color: var(--accent-cyan);
      box-shadow: 0 0 8px rgba(0, 245, 212, 0.25);
    }

    /* 页脚 Footer */
    footer.site-footer {
      background: #060709;
      padding: 80px 0 30px;
      border-top: 1px solid var(--border-color);
      font-size: 14px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 1.4fr 1fr 1fr 1.2fr;
      gap: 40px;
      margin-bottom: 50px;
    }
    .footer-brand h4 {
      font-size: 20px;
      font-weight: 800;
      margin-bottom: 14px;
      color: var(--text-white);
    }
    .footer-brand p {
      color: var(--text-muted);
      line-height: 1.7;
      margin-bottom: 18px;
      font-size: 13px;
    }
    .footer-contact-item {
      color: var(--text-dim);
      font-size: 13px;
      margin-bottom: 6px;
    }
    .footer-contact-item a {
      color: var(--accent-cyan);
    }
    .footer-col h5 {
      font-size: 15px;
      font-weight: 700;
      color: var(--text-white);
      margin-bottom: 18px;
    }
    .footer-links {
      list-style: none;
      display: flex;
      flex-direction: column;
      gap: 10px;
    }
    .footer-links a {
      color: var(--text-muted);
      font-size: 13px;
    }
    .footer-links a:hover {
      color: var(--accent-cyan);
      padding-left: 4px;
    }
    .footer-bottom {
      border-top: 1px solid var(--border-color);
      padding-top: 26px;
      display: flex;
      justify-content: space-between;
      align-items: center;
      color: var(--text-dim);
      font-size: 13px;
      flex-wrap: wrap;
      gap: 14px;
    }

    /* 移动端与全平台响应式断点 */
    @media (max-width: 1024px) {
      .hero-grid, .arch-grid, .compare-container, .story-layout, .cta-container, .news-grid {
        grid-template-columns: 1fr;
      }
      .features-grid, .pricing-grid, .timeline-wrap, .services-grid, .metrics-strip, .reviews-grid, .guarantee-grid, .footer-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .timeline-wrap::before {
        display: none;
      }
    }
    @media (max-width: 768px) {
      .mobile-toggle {
        display: block;
      }
      .nav-links {
        display: none;
        position: absolute;
        top: 70px;
        left: 0;
        right: 0;
        background: #0B0D11;
        flex-direction: column;
        padding: 24px;
        gap: 16px;
        border-bottom: 1px solid var(--border-color);
      }
      .nav-links.active {
        display: flex;
      }
      .hero-content h1 {
        font-size: 32px;
      }
      .features-grid, .pricing-grid, .timeline-wrap, .services-grid, .metrics-strip, .reviews-grid, .guarantee-grid, .footer-grid {
        grid-template-columns: 1fr;
      }
      .cta-container {
        padding: 30px 20px;
      }
      .hero-stats-strip {
        grid-template-columns: 1fr;
      }
    }