/* roulang page: index */
:root {
      --primary: #f97316;
      --primary-hover: #ea580c;
      --primary-glow: rgba(249, 115, 22, 0.25);
      --dark-bg: #0b0f19;
      --surface: #111827;
      --surface-border: #1f293d;
      --surface-card: #141e33;
      --text-main: #f3f4f6;
      --text-muted: #9ca3af;
      --text-dim: #6b7280;
      --accent: #38bdf8;
      --radius-sm: 8px;
      --radius-md: 14px;
      --radius-lg: 22px;
      --shadow-sm: 0 4px 12px rgba(0,0,0,0.3);
      --shadow-lg: 0 16px 36px rgba(0,0,0,0.45);
      --container-width: 1240px;
    }

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

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

    a {
      text-decoration: none;
      color: inherit;
      transition: all 0.25s ease;
    }

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

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

    /* 居中 Logo + 两侧导航版式 */
    .site-header {
      position: sticky;
      top: 0;
      z-index: 100;
      background: rgba(11, 15, 25, 0.88);
      backdrop-filter: blur(16px);
      border-bottom: 1px solid var(--surface-border);
      height: 76px;
      display: flex;
      align-items: center;
    }

    .nav-wrapper {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
    }

    .nav-side {
      display: flex;
      align-items: center;
      gap: 28px;
      flex: 1;
    }

    .nav-side.nav-left {
      justify-content: flex-end;
      padding-right: 48px;
    }

    .nav-side.nav-right {
      justify-content: flex-start;
      padding-left: 48px;
    }

    .nav-link {
      font-size: 15px;
      font-weight: 500;
      color: var(--text-muted);
      position: relative;
      padding: 6px 0;
    }

    .nav-link:hover, .nav-link.active {
      color: #fff;
    }

    .nav-link.active::after {
      content: '';
      position: absolute;
      bottom: -2px;
      left: 0;
      width: 100%;
      height: 2px;
      background: var(--primary);
      border-radius: 2px;
    }

    .brand-center {
      display: flex;
      flex-direction: column;
      align-items: center;
      text-align: center;
      padding: 0 12px;
    }

    .brand-logo-text {
      font-size: 24px;
      font-weight: 800;
      letter-spacing: 1.5px;
      background: linear-gradient(135deg, #fff 20%, var(--primary) 100%);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      line-height: 1.2;
    }

    .brand-badge {
      font-size: 10px;
      letter-spacing: 2px;
      text-transform: uppercase;
      color: var(--accent);
      font-weight: 600;
    }

    .nav-action-btn {
      display: inline-flex;
      align-items: center;
      gap: 6px;
      padding: 8px 18px;
      background: rgba(249, 115, 22, 0.12);
      border: 1px solid var(--primary);
      color: #fff;
      font-size: 14px;
      font-weight: 600;
      border-radius: var(--radius-sm);
    }

    .nav-action-btn:hover {
      background: var(--primary);
      box-shadow: 0 0 16px var(--primary-glow);
    }

    /* 响应式汉堡栏 */
    .mobile-menu-toggle {
      display: none;
      background: none;
      border: none;
      color: #fff;
      font-size: 24px;
      cursor: pointer;
    }

    /* Section 基础样式 */
    .section-wrap {
      padding: 96px 0;
      position: relative;
      border-bottom: 1px solid var(--surface-border);
    }

    .section-alt {
      background-color: var(--surface);
    }

    .section-heading-group {
      max-width: 820px;
      margin: 0 auto 56px auto;
      text-align: center;
    }

    .section-tag {
      display: inline-block;
      font-size: 12px;
      font-weight: 700;
      letter-spacing: 2px;
      text-transform: uppercase;
      color: var(--primary);
      background: rgba(249, 115, 22, 0.1);
      padding: 6px 14px;
      border-radius: 99px;
      margin-bottom: 16px;
      border: 1px solid rgba(249, 115, 22, 0.2);
    }

    .section-title {
      font-size: 32px;
      font-weight: 700;
      color: #fff;
      margin-bottom: 16px;
      line-height: 1.35;
    }

    .section-desc {
      font-size: 16px;
      color: var(--text-muted);
      line-height: 1.8;
    }

    /* Hero 全宽视频遮罩与控制区 */
    .hero-video-stage {
      position: relative;
      min-height: 620px;
      display: flex;
      align-items: center;
      justify-content: center;
      text-align: center;
      padding: 100px 24px;
      background: radial-gradient(circle at 50% 30%, rgba(30, 41, 59, 0.85) 0%, #0b0f19 90%);
      overflow: hidden;
      border-bottom: 1px solid var(--surface-border);
    }

    .hero-video-bg {
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      object-fit: cover;
      opacity: 0.28;
      filter: saturate(1.4) contrast(1.1);
      pointer-events: none;
    }

    .hero-glow-layer {
      position: absolute;
      top: 50%;
      left: 50%;
      transform: translate(-50%, -50%);
      width: 700px;
      height: 700px;
      background: radial-gradient(circle, rgba(249, 115, 22, 0.12) 0%, rgba(0,0,0,0) 70%);
      pointer-events: none;
    }

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

    .hero-eyebrow {
      display: inline-flex;
      align-items: center;
      gap: 8px;
      background: rgba(255, 255, 255, 0.05);
      border: 1px solid rgba(255, 255, 255, 0.12);
      padding: 8px 18px;
      border-radius: 99px;
      font-size: 13px;
      color: #e2e8f0;
      margin-bottom: 24px;
    }

    .hero-eyebrow .dot {
      width: 8px;
      height: 8px;
      background: var(--primary);
      border-radius: 50%;
      box-shadow: 0 0 10px var(--primary);
    }

    .hero-h1 {
      font-size: 46px;
      font-weight: 800;
      color: #fff;
      line-height: 1.25;
      letter-spacing: -0.5px;
      margin-bottom: 24px;
    }

    .hero-h1 span {
      background: linear-gradient(135deg, #f97316 0%, #fb923c 100%);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
    }

    .hero-p {
      font-size: 17px;
      color: var(--text-muted);
      line-height: 1.85;
      margin-bottom: 38px;
      max-width: 800px;
      margin-left: auto;
      margin-right: auto;
    }

    .hero-controls {
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 20px;
      flex-wrap: wrap;
    }

    .btn-main {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 10px;
      background: var(--primary);
      color: #fff;
      font-size: 16px;
      font-weight: 600;
      padding: 14px 34px;
      border-radius: var(--radius-sm);
      border: 1px solid var(--primary);
      cursor: pointer;
    }

    .btn-main:hover {
      background: var(--primary-hover);
      box-shadow: 0 0 24px var(--primary-glow);
      transform: translateY(-2px);
    }

    .btn-play-preview {
      display: inline-flex;
      align-items: center;
      gap: 12px;
      padding: 14px 28px;
      background: rgba(255, 255, 255, 0.08);
      border: 1px solid rgba(255, 255, 255, 0.18);
      border-radius: var(--radius-sm);
      color: #fff;
      font-size: 15px;
      font-weight: 600;
    }

    .btn-play-preview:hover {
      background: rgba(255, 255, 255, 0.15);
      border-color: rgba(255, 255, 255, 0.3);
    }

    .play-icon {
      width: 28px;
      height: 28px;
      background: #fff;
      color: #0b0f19;
      border-radius: 50%;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      font-size: 12px;
      padding-left: 2px;
    }

    /* 板块 2: 问题陈述 */
    .problem-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 28px;
    }

    .problem-box {
      background: var(--surface-card);
      border: 1px solid var(--surface-border);
      border-radius: var(--radius-md);
      padding: 36px 30px;
      position: relative;
    }

    .problem-badge {
      font-size: 12px;
      color: #ef4444;
      font-weight: 700;
      margin-bottom: 14px;
      display: block;
    }

    .problem-title {
      font-size: 20px;
      color: #fff;
      margin-bottom: 12px;
      font-weight: 700;
    }

    .problem-text {
      font-size: 14px;
      color: var(--text-muted);
      line-height: 1.75;
    }

    /* 板块 3: 操作演示 */
    .demo-showcase {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 48px;
      align-items: center;
    }

    .demo-viewport {
      background: #000;
      border: 1px solid var(--surface-border);
      border-radius: var(--radius-md);
      overflow: hidden;
      box-shadow: var(--shadow-lg);
    }

    .demo-bar {
      height: 38px;
      background: #172033;
      display: flex;
      align-items: center;
      padding: 0 16px;
      gap: 8px;
      border-bottom: 1px solid var(--surface-border);
    }

    .circle-dot {
      width: 10px;
      height: 10px;
      border-radius: 50%;
    }

    .circle-dot.red { background: #ef4444; }
    .circle-dot.yellow { background: #eab308; }
    .circle-dot.green { background: #22c55e; }

    .demo-code-area {
      padding: 24px;
      font-family: Consolas, Monaco, monospace;
      font-size: 13px;
      line-height: 1.8;
      color: #94a3b8;
    }

    .code-accent { color: var(--primary); }
    .code-cyan { color: var(--accent); }
    .code-white { color: #f8fafc; }

    .demo-steps-list {
      display: flex;
      flex-direction: column;
      gap: 22px;
    }

    .demo-step-item {
      display: flex;
      gap: 18px;
    }

    .step-index {
      width: 38px;
      height: 38px;
      border-radius: var(--radius-sm);
      background: rgba(249, 115, 22, 0.15);
      border: 1px solid var(--primary);
      color: var(--primary);
      font-size: 16px;
      font-weight: 700;
      display: flex;
      align-items: center;
      justify-content: center;
      flex-shrink: 0;
    }

    .step-title {
      font-size: 17px;
      font-weight: 700;
      color: #fff;
      margin-bottom: 6px;
    }

    .step-desc {
      font-size: 14px;
      color: var(--text-muted);
      line-height: 1.7;
    }

    /* 板块 4: 结果预览 */
    .preview-mosaic {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 20px;
    }

    .preview-card {
      background: var(--surface-card);
      border: 1px solid var(--surface-border);
      border-radius: var(--radius-md);
      overflow: hidden;
      transition: transform 0.3s ease, border-color 0.3s ease;
    }

    .preview-card:hover {
      transform: translateY(-4px);
      border-color: var(--primary);
    }

    .preview-thumb {
      height: 180px;
      background: #1e293b;
      display: flex;
      align-items: center;
      justify-content: center;
      position: relative;
      overflow: hidden;
    }

    .preview-thumb-inner {
      width: 100%;
      height: 100%;
      background: linear-gradient(135deg, #1e293b 0%, #0f172a 100%);
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      color: #475569;
      font-size: 13px;
      font-weight: 600;
      padding: 16px;
      text-align: center;
    }

    .preview-badge-status {
      position: absolute;
      top: 12px;
      right: 12px;
      background: rgba(0, 0, 0, 0.7);
      backdrop-filter: blur(4px);
      font-size: 11px;
      color: var(--accent);
      padding: 4px 10px;
      border-radius: 4px;
      border: 1px solid rgba(56, 189, 248, 0.3);
    }

    .preview-info {
      padding: 20px;
    }

    .preview-item-title {
      font-size: 16px;
      font-weight: 700;
      color: #fff;
      margin-bottom: 8px;
    }

    .preview-item-desc {
      font-size: 13px;
      color: var(--text-muted);
      line-height: 1.6;
    }

    /* 板块 5: 常见卡住点 */
    .stuck-points-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }

    .stuck-card {
      background: rgba(17, 24, 39, 0.6);
      border: 1px solid var(--surface-border);
      border-radius: var(--radius-md);
      padding: 30px;
    }

    .stuck-icon-wrap {
      width: 44px;
      height: 44px;
      border-radius: var(--radius-sm);
      background: rgba(239, 68, 68, 0.1);
      border: 1px solid rgba(239, 68, 68, 0.25);
      color: #ef4444;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 800;
      font-size: 18px;
      margin-bottom: 18px;
    }

    .stuck-card-h {
      font-size: 18px;
      font-weight: 700;
      color: #fff;
      margin-bottom: 10px;
    }

    .stuck-card-p {
      font-size: 14px;
      color: var(--text-muted);
      line-height: 1.7;
    }

    /* 板块 6: 成功路径 */
    .success-path-timeline {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
      position: relative;
    }

    .path-step-card {
      background: var(--surface-card);
      border: 1px solid var(--surface-border);
      border-radius: var(--radius-md);
      padding: 28px 24px;
      position: relative;
    }

    .path-num {
      font-size: 32px;
      font-weight: 900;
      color: var(--primary);
      opacity: 0.6;
      line-height: 1;
      margin-bottom: 14px;
    }

    .path-step-title {
      font-size: 17px;
      font-weight: 700;
      color: #fff;
      margin-bottom: 8px;
    }

    .path-step-detail {
      font-size: 13px;
      color: var(--text-muted);
      line-height: 1.65;
    }

    /* 板块 7: 参数速览 */
    .specs-table-wrapper {
      background: var(--surface-card);
      border: 1px solid var(--surface-border);
      border-radius: var(--radius-md);
      overflow: hidden;
      max-width: 960px;
      margin: 0 auto;
    }

    .specs-row {
      display: grid;
      grid-template-columns: 240px 1fr;
      border-bottom: 1px solid var(--surface-border);
    }

    .specs-row:last-child {
      border-bottom: none;
    }

    .specs-key {
      background: rgba(255, 255, 255, 0.02);
      padding: 18px 24px;
      font-size: 14px;
      font-weight: 600;
      color: #cbd5e1;
      border-right: 1px solid var(--surface-border);
    }

    .specs-value {
      padding: 18px 24px;
      font-size: 14px;
      color: var(--text-muted);
      line-height: 1.6;
    }

    /* 板块 8: 热门专题 */
    .topics-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }

    .topic-item {
      background: var(--surface-card);
      border: 1px solid var(--surface-border);
      border-radius: var(--radius-md);
      padding: 28px;
      display: flex;
      flex-direction: column;
      justify-content: space-between;
      min-height: 200px;
    }

    .topic-tag {
      font-size: 12px;
      font-weight: 600;
      color: var(--accent);
      margin-bottom: 10px;
    }

    .topic-name {
      font-size: 19px;
      font-weight: 700;
      color: #fff;
      margin-bottom: 12px;
    }

    .topic-desc {
      font-size: 13px;
      color: var(--text-muted);
      line-height: 1.6;
    }

    /* 板块 9: 资讯列表 */
    .news-stream-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 28px;
    }

    .news-card {
      background: var(--surface-card);
      border: 1px solid var(--surface-border);
      border-radius: var(--radius-md);
      padding: 30px;
      display: flex;
      flex-direction: column;
    }

    .news-meta {
      display: flex;
      align-items: center;
      gap: 12px;
      font-size: 12px;
      color: var(--text-dim);
      margin-bottom: 14px;
    }

    .news-badge {
      color: var(--primary);
      font-weight: 600;
    }

    .news-h {
      font-size: 18px;
      font-weight: 700;
      color: #fff;
      margin-bottom: 12px;
      line-height: 1.45;
    }

    .news-p {
      font-size: 14px;
      color: var(--text-muted);
      line-height: 1.7;
      flex-grow: 1;
      margin-bottom: 20px;
    }

    .news-read-more {
      font-size: 13px;
      font-weight: 600;
      color: var(--accent);
      display: inline-flex;
      align-items: center;
      gap: 6px;
    }

    /* 板块 10: 资质与规范背书 */
    .cert-row {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 20px;
    }

    .cert-item {
      background: var(--surface-card);
      border: 1px solid var(--surface-border);
      border-radius: var(--radius-md);
      padding: 24px;
      text-align: center;
    }

    .cert-shield {
      width: 48px;
      height: 48px;
      margin: 0 auto 16px auto;
      background: rgba(56, 189, 248, 0.1);
      border: 1px solid rgba(56, 189, 248, 0.25);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      color: var(--accent);
      font-size: 20px;
    }

    .cert-name {
      font-size: 16px;
      font-weight: 700;
      color: #fff;
      margin-bottom: 8px;
    }

    .cert-desc {
      font-size: 12px;
      color: var(--text-muted);
      line-height: 1.6;
    }

    /* 板块 11: 开始使用与协作转化 (整页唯一收口) */
    .action-cta-box {
      background: linear-gradient(135deg, #1f293d 0%, #111827 100%);
      border: 1px solid rgba(249, 115, 22, 0.3);
      border-radius: var(--radius-lg);
      padding: 72px 48px;
      text-align: center;
      position: relative;
      overflow: hidden;
      box-shadow: var(--shadow-lg);
    }

    .cta-title {
      font-size: 34px;
      font-weight: 800;
      color: #fff;
      margin-bottom: 18px;
    }

    .cta-desc {
      max-width: 680px;
      margin: 0 auto 36px auto;
      font-size: 16px;
      color: var(--text-muted);
      line-height: 1.8;
    }

    .cta-actions {
      display: flex;
      justify-content: center;
      gap: 18px;
      flex-wrap: wrap;
    }

    /* 页脚 */
    .site-footer {
      background-color: #070a12;
      border-top: 1px solid var(--surface-border);
      padding: 72px 0 36px 0;
      color: var(--text-muted);
      font-size: 14px;
    }

    .footer-top {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 48px;
      margin-bottom: 56px;
    }

    .footer-brand-title {
      font-size: 22px;
      font-weight: 800;
      color: #fff;
      margin-bottom: 16px;
      letter-spacing: 1px;
    }

    .footer-brand-summary {
      font-size: 14px;
      color: var(--text-muted);
      line-height: 1.8;
      max-width: 360px;
      margin-bottom: 20px;
    }

    .footer-col-h {
      font-size: 15px;
      font-weight: 700;
      color: #fff;
      margin-bottom: 20px;
      letter-spacing: 0.5px;
    }

    .footer-links-list {
      list-style: none;
      display: flex;
      flex-direction: column;
      gap: 12px;
    }

    .footer-links-list a {
      color: var(--text-muted);
    }

    .footer-links-list a:hover {
      color: var(--primary);
    }

    .footer-bottom {
      border-top: 1px solid rgba(255, 255, 255, 0.06);
      padding-top: 32px;
      display: flex;
      justify-content: space-between;
      align-items: center;
      flex-wrap: wrap;
      gap: 16px;
      color: var(--text-dim);
      font-size: 13px;
    }

    /* 响应式断点 */
    @media (max-width: 1024px) {
      .preview-mosaic {
        grid-template-columns: repeat(2, 1fr);
      }
      .success-path-timeline {
        grid-template-columns: repeat(2, 1fr);
      }
      .cert-row {
        grid-template-columns: repeat(2, 1fr);
      }
      .footer-top {
        grid-template-columns: 1fr 1fr;
      }
    }

    @media (max-width: 768px) {
      .nav-side {
        display: none;
      }
      .mobile-menu-toggle {
        display: block;
      }
      .demo-showcase {
        grid-template-columns: 1fr;
      }
      .problem-grid,
      .stuck-points-grid,
      .topics-grid,
      .news-stream-grid {
        grid-template-columns: 1fr;
      }
      .specs-row {
        grid-template-columns: 1fr;
      }
      .specs-key {
        border-right: none;
        border-bottom: 1px solid var(--surface-border);
      }
      .hero-h1 {
        font-size: 32px;
      }
      .action-cta-box {
        padding: 48px 24px;
      }
    }

    @media (max-width: 520px) {
      .preview-mosaic,
      .success-path-timeline,
      .cert-row {
        grid-template-columns: 1fr;
      }
      .footer-top {
        grid-template-columns: 1fr;
      }
      .hero-video-stage {
        padding: 60px 16px;
      }
    }