/* roulang page: index */
:root {
      --primary: #0F62FE;
      --primary-hover: #0043CE;
      --primary-light: #EBF2FF;
      --accent: #10B981;
      --accent-warm: #F59E0B;
      --dark: #0B132B;
      --dark-card: #1C2541;
      --text-main: #0F172A;
      --text-muted: #334155;
      --text-light: #64748B;
      --bg-light: #F8FAFC;
      --bg-white: #FFFFFF;
      --border-color: #E2E8F0;
      --radius-sm: 8px;
      --radius-md: 14px;
      --radius-lg: 20px;
      --shadow-sm: 0 2px 8px rgba(15, 23, 42, 0.04);
      --shadow-md: 0 8px 24px -4px rgba(15, 23, 42, 0.08);
      --shadow-lg: 0 16px 36px -6px rgba(15, 23, 42, 0.12);
      --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    }

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

    html {
      scroll-behavior: smooth;
      font-family: system-ui, -apple-system, "PingFang SC", "Microsoft YaHei", "Segoe UI", Roboto, sans-serif;
      color: var(--text-main);
      background-color: var(--bg-light);
      line-height: 1.6;
    }

    body {
      overflow-x: hidden;
      -webkit-font-smoothing: antialiased;
    }

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

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

    .container {
      width: 100%;
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 24px;
    }

    /* 顶部通栏公告与导航 */
    .top-bar {
      background-color: var(--dark);
      color: #94A3B8;
      font-size: 13px;
      padding: 8px 0;
      border-bottom: 1px solid rgba(255, 255, 255, 0.08);
    }
    .top-bar .container {
      display: flex;
      justify-content: space-between;
      align-items: center;
      flex-wrap: wrap;
      gap: 10px;
    }
    .top-badge {
      background: rgba(16, 185, 129, 0.2);
      color: var(--accent);
      padding: 2px 8px;
      border-radius: 4px;
      font-size: 12px;
      font-weight: 600;
      margin-right: 8px;
    }

    .site-header {
      position: sticky;
      top: 0;
      z-index: 1000;
      background: rgba(255, 255, 255, 0.95);
      backdrop-filter: blur(12px);
      border-bottom: 1px solid var(--border-color);
      transition: var(--transition);
    }
    .header-inner {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 72px;
    }
    .logo-area {
      display: flex;
      align-items: center;
      gap: 12px;
      font-size: 22px;
      font-weight: 800;
      color: var(--primary);
    }
    .logo-icon {
      width: 38px;
      height: 38px;
      background: linear-gradient(135deg, var(--primary), #00C7D9);
      border-radius: 10px;
      display: flex;
      align-items: center;
      justify-content: center;
      color: #FFF;
      font-size: 20px;
      font-weight: bold;
    }
    .nav-menu {
      display: flex;
      list-style: none;
      gap: 28px;
      align-items: center;
    }
    .nav-menu a {
      font-size: 15px;
      font-weight: 500;
      color: var(--text-muted);
    }
    .nav-menu a:hover, .nav-menu a.active {
      color: var(--primary);
    }

    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      padding: 12px 26px;
      font-size: 15px;
      font-weight: 600;
      border-radius: var(--radius-sm);
      cursor: pointer;
      transition: var(--transition);
      border: 1px solid transparent;
    }
    .btn-primary {
      background-color: var(--primary);
      color: #FFFFFF;
      box-shadow: 0 4px 14px rgba(15, 98, 254, 0.3);
    }
    .btn-primary:hover {
      background-color: var(--primary-hover);
      transform: translateY(-2px);
      box-shadow: 0 6px 20px rgba(15, 98, 254, 0.4);
    }
    .btn-secondary {
      background-color: rgba(255, 255, 255, 0.15);
      color: #FFFFFF;
      border: 1px solid rgba(255, 255, 255, 0.3);
      backdrop-filter: blur(8px);
    }
    .btn-secondary:hover {
      background-color: rgba(255, 255, 255, 0.25);
      transform: translateY(-2px);
    }
    .btn-outline {
      background-color: transparent;
      color: var(--primary);
      border-color: var(--primary);
    }
    .btn-outline:hover {
      background-color: var(--primary-light);
    }

    /* 板块通用 */
    section {
      padding: 80px 0;
      position: relative;
    }
    .section-dark {
      background-color: var(--dark);
      color: #FFFFFF;
    }
    .section-white {
      background-color: var(--bg-white);
    }
    .section-light {
      background-color: var(--bg-light);
    }
    .section-header {
      margin-bottom: 48px;
      text-align: center;
    }
    .section-tag {
      display: inline-block;
      font-size: 13px;
      font-weight: 700;
      letter-spacing: 1px;
      text-transform: uppercase;
      color: var(--primary);
      background-color: var(--primary-light);
      padding: 4px 12px;
      border-radius: 20px;
      margin-bottom: 12px;
    }
    .section-dark .section-tag {
      background: rgba(15, 98, 254, 0.2);
      color: #60A5FA;
    }
    .section-title {
      font-size: 32px;
      font-weight: 700;
      margin-bottom: 16px;
      line-height: 1.3;
    }
    .section-desc {
      font-size: 16px;
      color: var(--text-light);
      max-width: 760px;
      margin: 0 auto;
      line-height: 1.7;
    }
    .section-dark .section-desc {
      color: #94A3B8;
    }

    /* 1. Hero 视频全宽遮罩看板区 */
    .hero-section {
      position: relative;
      min-height: 560px;
      background: linear-gradient(135deg, rgba(11, 19, 43, 0.88), rgba(15, 23, 42, 0.82)), url('/assets/images/ef81529fe7ccaea2.webp') center/cover no-repeat;
      display: flex;
      align-items: center;
      color: #FFFFFF;
      padding: 100px 0 90px;
    }
    .hero-content {
      max-width: 820px;
    }
    .hero-badge {
      display: inline-flex;
      align-items: center;
      gap: 8px;
      background: rgba(255, 255, 255, 0.12);
      border: 1px solid rgba(255, 255, 255, 0.2);
      padding: 6px 16px;
      border-radius: 30px;
      font-size: 14px;
      margin-bottom: 24px;
    }
    .hero-title {
      font-size: 46px;
      font-weight: 800;
      line-height: 1.25;
      margin-bottom: 20px;
      letter-spacing: -0.5px;
    }
    .hero-title span {
      background: linear-gradient(90deg, #60A5FA, #34D399);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
    }
    .hero-desc {
      font-size: 17px;
      color: #CBD5E1;
      line-height: 1.8;
      margin-bottom: 36px;
    }
    .hero-actions {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
      align-items: center;
    }

    /* 2. 已上线核心能力 (3列卡片) */
    .feature-grid-3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 28px;
    }
    .feature-card {
      background: #FFFFFF;
      border-radius: var(--radius-md);
      padding: 32px;
      border: 1px solid var(--border-color);
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
      display: flex;
      flex-direction: column;
    }
    .feature-card:hover {
      transform: translateY(-5px);
      box-shadow: var(--shadow-md);
      border-color: var(--primary);
    }
    .feature-icon-box {
      width: 52px;
      height: 52px;
      border-radius: 12px;
      background: var(--primary-light);
      color: var(--primary);
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 22px;
      font-weight: bold;
      margin-bottom: 20px;
    }
    .feature-card h3 {
      font-size: 20px;
      margin-bottom: 12px;
      color: var(--text-main);
    }
    .feature-card p {
      font-size: 14px;
      color: var(--text-muted);
      line-height: 1.7;
    }

    /* 3. 正在研发与接入板块 (Bento Grid) */
    .bento-grid {
      display: grid;
      grid-template-columns: repeat(12, 1fr);
      gap: 24px;
    }
    .bento-card {
      background: #FFFFFF;
      border-radius: var(--radius-md);
      padding: 30px;
      border: 1px solid var(--border-color);
      box-shadow: var(--shadow-sm);
      position: relative;
      overflow: hidden;
    }
    .bento-card-8 { grid-column: span 8; }
    .bento-card-4 { grid-column: span 4; }
    .bento-card-6 { grid-column: span 6; }
    .status-badge {
      display: inline-flex;
      align-items: center;
      gap: 6px;
      padding: 4px 10px;
      border-radius: 6px;
      font-size: 12px;
      font-weight: 600;
      margin-bottom: 14px;
    }
    .status-running {
      background: #FEF3C7;
      color: #D97706;
    }
    .status-planning {
      background: #E0E7FF;
      color: #4F46E5;
    }
    .progress-bar-wrap {
      margin-top: 20px;
      background: #F1F5F9;
      border-radius: 20px;
      height: 8px;
      overflow: hidden;
    }
    .progress-bar-fill {
      height: 100%;
      background: linear-gradient(90deg, var(--primary), var(--accent));
      border-radius: 20px;
    }

    /* 4. 自适应算法与技术底座 */
    .tech-box {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 40px;
      align-items: center;
    }
    .tech-list {
      list-style: none;
      display: flex;
      flex-direction: column;
      gap: 16px;
      margin-top: 24px;
    }
    .tech-item {
      display: flex;
      gap: 14px;
      align-items: flex-start;
    }
    .tech-bullet {
      width: 20px;
      height: 20px;
      border-radius: 50%;
      background: var(--accent);
      color: #FFF;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 12px;
      margin-top: 3px;
      flex-shrink: 0;
    }

    /* 5. 典型应用场景与流程拆解 */
    .step-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 20px;
      position: relative;
    }
    .step-card {
      background: #FFFFFF;
      padding: 28px 20px;
      border-radius: var(--radius-md);
      border: 1px solid var(--border-color);
      text-align: center;
      position: relative;
    }
    .step-num {
      width: 40px;
      height: 40px;
      line-height: 40px;
      background: var(--primary);
      color: #FFF;
      border-radius: 50%;
      margin: 0 auto 16px;
      font-weight: 700;
      font-size: 16px;
    }

    /* 6. 核心业务关键指标条 */
    .metrics-band {
      background: linear-gradient(135deg, #0F62FE, #0043CE);
      color: #FFF;
      padding: 50px 0;
    }
    .metrics-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
      text-align: center;
    }
    .metric-val {
      font-size: 42px;
      font-weight: 800;
      line-height: 1;
      margin-bottom: 8px;
      letter-spacing: -1px;
    }
    .metric-label {
      font-size: 14px;
      color: #BFDBFE;
    }

    /* 7. 方案与多角色赋能 */
    .solution-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 30px;
    }
    .solution-card {
      background: #FFF;
      border-radius: var(--radius-md);
      overflow: hidden;
      border: 1px solid var(--border-color);
      box-shadow: var(--shadow-sm);
      display: flex;
      flex-direction: column;
    }
    .solution-img {
      height: 200px;
      width: 100%;
    }
    .solution-body {
      padding: 26px;
      flex-grow: 1;
      display: flex;
      flex-direction: column;
    }
    .solution-body h3 {
      font-size: 19px;
      margin-bottom: 10px;
    }

    /* 8. 真实教学实测对比墙 */
    .story-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 30px;
    }
    .story-card {
      background: #FFF;
      border-radius: var(--radius-md);
      padding: 30px;
      border: 1px solid var(--border-color);
      display: flex;
      flex-direction: column;
      gap: 16px;
    }
    .stat-compare-box {
      display: flex;
      gap: 16px;
      background: var(--bg-light);
      padding: 16px;
      border-radius: var(--radius-sm);
      margin-top: auto;
    }
    .stat-compare-item {
      flex: 1;
    }
    .stat-compare-num {
      font-size: 22px;
      font-weight: 700;
      color: var(--primary);
    }

    /* 9. 版本迭代与更新日志 */
    .log-timeline {
      max-width: 860px;
      margin: 0 auto;
      border-left: 2px solid var(--border-color);
      padding-left: 30px;
      display: flex;
      flex-direction: column;
      gap: 32px;
    }
    .log-item {
      position: relative;
    }
    .log-item::before {
      content: "";
      position: absolute;
      left: -37px;
      top: 4px;
      width: 12px;
      height: 12px;
      border-radius: 50%;
      background: var(--primary);
      border: 2px solid #FFF;
      box-shadow: 0 0 0 2px var(--primary);
    }
    .log-ver {
      font-size: 18px;
      font-weight: 700;
      color: var(--text-main);
      margin-bottom: 6px;
      display: flex;
      align-items: center;
      gap: 12px;
    }
    .log-date {
      font-size: 13px;
      color: var(--text-light);
      font-weight: normal;
    }
    .log-desc {
      font-size: 14px;
      color: var(--text-muted);
    }

    /* 10. AI教育资讯与技术视界 */
    .news-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 28px;
    }
    .news-card {
      background: #FFFFFF;
      border-radius: var(--radius-md);
      overflow: hidden;
      border: 1px solid var(--border-color);
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
    }
    .news-card:hover {
      box-shadow: var(--shadow-md);
      transform: translateY(-3px);
    }
    .news-card img {
      height: 190px;
      width: 100%;
    }
    .news-body {
      padding: 22px;
    }
    .news-meta {
      font-size: 12px;
      color: var(--text-light);
      margin-bottom: 8px;
      display: flex;
      justify-content: space-between;
    }
    .news-body h3 {
      font-size: 17px;
      line-height: 1.4;
      margin-bottom: 10px;
    }

    /* 11. 常见问题手风琴 */
    .faq-container {
      max-width: 860px;
      margin: 0 auto;
      display: flex;
      flex-direction: column;
      gap: 14px;
    }
    .faq-item {
      background: #FFFFFF;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-sm);
      overflow: hidden;
    }
    .faq-item details summary {
      padding: 18px 24px;
      font-size: 16px;
      font-weight: 600;
      cursor: pointer;
      list-style: none;
      display: flex;
      justify-content: space-between;
      align-items: center;
      user-select: none;
    }
    .faq-item details summary::-webkit-details-marker {
      display: none;
    }
    .faq-item details summary::after {
      content: '+';
      font-size: 20px;
      color: var(--primary);
      transition: transform 0.2s;
    }
    .faq-item details[open] summary::after {
      content: '−';
    }
    .faq-content {
      padding: 0 24px 20px;
      font-size: 14px;
      color: var(--text-muted);
      line-height: 1.7;
    }

    /* 12. 转化保障与在线试用预约 */
    .cta-card {
      background: linear-gradient(135deg, #0B132B, #1C2541);
      border-radius: var(--radius-lg);
      padding: 60px 40px;
      color: #FFF;
      text-align: center;
      border: 1px solid rgba(255, 255, 255, 0.1);
      box-shadow: var(--shadow-lg);
    }
    .cta-card h2 {
      font-size: 34px;
      margin-bottom: 16px;
    }
    .cta-card p {
      font-size: 16px;
      color: #94A3B8;
      max-width: 680px;
      margin: 0 auto 36px;
    }
    .cta-form {
      display: flex;
      max-width: 540px;
      margin: 0 auto;
      gap: 12px;
    }
    .cta-input {
      flex: 1;
      padding: 14px 20px;
      border-radius: var(--radius-sm);
      border: 1px solid rgba(255, 255, 255, 0.2);
      background: rgba(255, 255, 255, 0.08);
      color: #FFFFFF;
      font-size: 15px;
      outline: none;
    }
    .cta-input::placeholder {
      color: #64748B;
    }
    .cta-input:focus {
      border-color: var(--primary);
      background: rgba(255, 255, 255, 0.14);
    }

    /* 页脚 */
    .site-footer {
      background-color: #060B19;
      color: #94A3B8;
      padding: 60px 0 30px;
      border-top: 1px solid rgba(255, 255, 255, 0.06);
      font-size: 14px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
      margin-bottom: 40px;
    }
    .footer-logo {
      font-size: 20px;
      font-weight: 700;
      color: #FFF;
      margin-bottom: 14px;
    }
    .footer-col h4 {
      color: #FFF;
      font-size: 15px;
      margin-bottom: 16px;
    }
    .footer-links {
      list-style: none;
      display: flex;
      flex-direction: column;
      gap: 10px;
    }
    .footer-links a:hover {
      color: #FFF;
    }
    .footer-bottom {
      padding-top: 24px;
      border-top: 1px solid rgba(255, 255, 255, 0.06);
      display: flex;
      justify-content: space-between;
      align-items: center;
      flex-wrap: wrap;
      gap: 12px;
      font-size: 13px;
    }

    /* 响应式断点适配 */
    @media (max-width: 1024px) {
      .feature-grid-3, .solution-grid, .news-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .bento-card-8, .bento-card-4, .bento-card-6 {
        grid-column: span 12;
      }
      .step-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .tech-box {
        grid-template-columns: 1fr;
      }
      .footer-grid {
        grid-template-columns: 1fr 1fr;
      }
    }

    @media (max-width: 768px) {
      .hero-title {
        font-size: 30px;
      }
      .nav-menu {
        display: none;
      }
      .feature-grid-3, .solution-grid, .news-grid, .story-grid, .metrics-grid, .step-grid {
        grid-template-columns: 1fr;
      }
      .cta-form {
        flex-direction: column;
      }
      .footer-grid {
        grid-template-columns: 1fr;
      }
      .footer-bottom {
        flex-direction: column;
        text-align: center;
      }
      section {
        padding: 50px 0;
      }
    }