/* roulang page: index */
* {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    :root {
      --cyan: #00F0FF;
      --deep-black: #0A0E17;
      --night-blue: #111827;
      --violet: #A855F7;
      --text-main: #F1F5F9;
      --text-body: #94A3B8;
      --text-sub: #CBD5E1;
      --border-glass: rgba(0, 240, 255, 0.15);
      --card-bg: rgba(17, 24, 39, 0.6);
      --radius-card: 16px;
      --shadow-card: 0 8px 32px rgba(0, 0, 0, 0.4);
      --container-max: 1280px;
      --section-padding: 80px;
      --gap: 24px;
      --font-stack: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans SC", sans-serif;
    }
    body {
      font-family: var(--font-stack);
      background: var(--deep-black);
      color: var(--text-body);
      line-height: 1.7;
      font-size: 1rem;
      -webkit-font-smoothing: antialiased;
    }
    a, button {
      transition: all 0.25s ease;
    }
    img {
      display: block;
      max-width: 100%;
      height: auto;
    }
    h1, h2, h3 {
      color: var(--text-main);
    }
    h1 {
      font-size: clamp(2.5rem, 6vw, 4rem);
      font-weight: 800;
      letter-spacing: -0.02em;
      line-height: 1.2;
    }
    h2 {
      font-size: 2.25rem;
      font-weight: 700;
      letter-spacing: -0.01em;
    }
    h3 {
      font-size: 1.25rem;
      font-weight: 600;
    }
    .container {
      max-width: var(--container-max);
      margin: 0 auto;
      padding: 0 20px;
    }
    section {
      padding: var(--section-padding) 0;
    }
    @media (max-width: 768px) {
      section {
        padding: 60px 0;
      }
      h2 {
        font-size: 1.8rem;
      }
    }

    /* 导航栏 */
    .navbar {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      background: rgba(10, 14, 23, 0.8);
      backdrop-filter: blur(16px);
      -webkit-backdrop-filter: blur(16px);
      border-bottom: 1px solid rgba(0, 240, 255, 0.2);
      z-index: 999;
      padding: 0 20px;
    }
    .nav-container {
      max-width: var(--container-max);
      margin: 0 auto;
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 70px;
    }
    .logo {
      font-size: 1.7rem;
      font-weight: 800;
      color: var(--text-main);
      text-decoration: none;
      letter-spacing: -0.5px;
      display: flex;
      align-items: center;
      gap: 6px;
    }
    .logo i {
      color: var(--cyan);
      font-size: 2rem;
    }
    .nav-menu {
      display: flex;
      align-items: center;
      gap: 28px;
    }
    .nav-menu a {
      color: var(--text-sub);
      text-decoration: none;
      font-weight: 500;
      font-size: 0.95rem;
      position: relative;
    }
    .nav-menu a:hover,
    .nav-menu a.active {
      color: var(--cyan);
    }
    .nav-menu a.active::after {
      content: '';
      position: absolute;
      bottom: -6px;
      left: 0;
      width: 100%;
      height: 2px;
      background: var(--cyan);
    }
    .btn-primary {
      background: var(--cyan);
      color: var(--deep-black);
      border: none;
      padding: 10px 24px;
      border-radius: 8px;
      font-weight: 700;
      font-size: 0.95rem;
      cursor: pointer;
      text-decoration: none;
      display: inline-block;
      letter-spacing: 0.3px;
    }
    .btn-primary:hover {
      box-shadow: 0 0 20px rgba(0, 240, 255, 0.6);
      transform: scale(1.03);
    }
    .btn-ghost {
      background: transparent;
      border: 1px solid var(--cyan);
      color: var(--cyan);
      padding: 10px 24px;
      border-radius: 8px;
      font-weight: 600;
      text-decoration: none;
      display: inline-block;
    }
    .btn-ghost:hover {
      background: rgba(0, 240, 255, 0.1);
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
    }
    .hamburger span {
      width: 28px;
      height: 3px;
      background: var(--text-main);
      border-radius: 3px;
    }
    @media (max-width: 768px) {
      .nav-menu {
        position: fixed;
        top: 70px;
        left: 0;
        width: 100%;
        background: rgba(10, 14, 23, 0.9);
        backdrop-filter: blur(20px);
        flex-direction: column;
        padding: 30px 20px;
        gap: 24px;
        transform: translateY(-150%);
        transition: transform 0.3s ease;
        border-bottom: 1px solid var(--border-glass);
      }
      .nav-menu.open {
        transform: translateY(0);
      }
      .hamburger {
        display: flex;
      }
      .nav-cta-desktop {
        display: none;
      }
    }

    /* Hero */
    .hero {
      position: relative;
      min-height: 100vh;
      display: flex;
      align-items: center;
      background: radial-gradient(circle at 30% 40%, rgba(0,240,255,0.08) 0%, transparent 60%),
                  url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      background-blend-mode: overlay;
      margin-top: 0;
      padding-top: 100px;
    }
    .hero-content {
      max-width: 700px;
      position: relative;
      z-index: 2;
    }
    .hero h1 span {
      color: var(--cyan);
    }
    .hero p {
      font-size: 1.2rem;
      color: var(--text-sub);
      margin: 24px 0 32px;
      max-width: 600px;
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }

    /* 核心优势 不对称网格 */
    .features-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: var(--gap);
      max-width: 900px;
      margin: 40px auto 0;
    }
    .feature-card {
      background: var(--card-bg);
      backdrop-filter: blur(12px);
      border: 1px solid var(--border-glass);
      border-radius: var(--radius-card);
      padding: 32px 24px;
      box-shadow: var(--shadow-card);
      transition: all 0.3s;
    }
    .feature-card:hover {
      border-color: var(--cyan);
      box-shadow: 0 0 28px rgba(0, 240, 255, 0.3);
    }
    .feature-card img {
      width: 48px;
      height: 48px;
      margin-bottom: 18px;
    }
    .feature-card.center-card {
      grid-column: span 2;
      justify-self: center;
      width: 65%;
    }
    @media (max-width: 768px) {
      .features-grid {
        grid-template-columns: 1fr;
      }
      .feature-card.center-card {
        grid-column: span 1;
        width: 100%;
      }
    }

    /* 产品服务 左标题右矩阵 */
    .products-wrapper {
      display: flex;
      gap: 48px;
      align-items: flex-start;
      flex-wrap: wrap;
    }
    .products-left {
      flex: 1 1 280px;
    }
    .products-right {
      flex: 2 1 500px;
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: var(--gap);
    }
    .product-card {
      background: var(--card-bg);
      backdrop-filter: blur(12px);
      border: 1px solid var(--border-glass);
      border-radius: var(--radius-card);
      padding: 28px 20px;
      transition: 0.3s;
      box-shadow: var(--shadow-card);
    }
    .product-card:hover {
      transform: translateY(-6px);
      border-color: var(--cyan);
      box-shadow: 0 12px 30px rgba(0, 240, 255, 0.25);
    }
    @media (max-width: 768px) {
      .products-right {
        grid-template-columns: 1fr;
      }
    }

    /* 使用场景 */
    .scenarios-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: var(--gap);
      margin-top: 40px;
    }
    .scene-card {
      background: var(--card-bg);
      backdrop-filter: blur(12px);
      border-radius: var(--radius-card);
      overflow: hidden;
      border: 1px solid var(--border-glass);
      transition: 0.3s;
    }
    .scene-card:hover {
      border-color: var(--cyan);
      box-shadow: 0 8px 24px rgba(0,240,255,0.2);
    }
    .scene-card img {
      width: 100%;
      height: 180px;
      object-fit: cover;
    }
    .scene-body {
      padding: 20px;
    }
    @media (max-width: 768px) {
      .scenarios-grid {
        grid-template-columns: 1fr;
      }
    }

    /* 数据案例 */
    .cases-split {
      display: flex;
      gap: 48px;
      flex-wrap: wrap;
      align-items: center;
    }
    .stats-left {
      flex: 1;
      display: flex;
      flex-direction: column;
      gap: 28px;
    }
    .stat-item h3 {
      font-size: 2.8rem;
      color: var(--violet);
    }
    .quote-right {
      flex: 1;
      background: rgba(168,85,247,0.08);
      padding: 32px;
      border-radius: var(--radius-card);
      font-style: italic;
      position: relative;
    }
    .quote-right::before {
      content: "“";
      font-size: 5rem;
      color: var(--cyan);
      position: absolute;
      top: -20px;
      left: 10px;
      opacity: 0.3;
    }

    /* FAQ */
    .faq-item {
      border-bottom: 1px solid var(--border-glass);
      padding: 18px 0;
      cursor: pointer;
    }
    .faq-question {
      display: flex;
      justify-content: space-between;
      font-weight: 600;
      color: var(--text-main);
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease;
      background: rgba(168,85,247,0.05);
      padding-left: 12px;
      border-left: 3px solid var(--violet);
      margin-top: 10px;
      color: var(--text-body);
    }
    .faq-item.open .faq-answer {
      max-height: 200px;
      padding: 12px 12px;
    }

    /* CTA */
    .cta-dark {
      background: #05080F;
      text-align: center;
    }
    /* footer */
    .footer-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 32px;
      background: #05080F;
      padding: 60px 0 30px;
      color: #64748B;
    }
    .footer-grid a {
      color: #64748B;
      text-decoration: none;
    }
    .footer-grid a:hover {
      color: var(--cyan);
    }
    @media (max-width: 768px) {
      .footer-grid {
        grid-template-columns: 1fr 1fr;
      }
    }