/* roulang page: index */
:root {
      --primary: #0A0E27;
      --accent: #00F0FF;
      --green: #00E676;
      --orange: #FF9100;
      --red: #FF1744;
      --text: #E8ECF1;
      --muted: #8892A6;
      --bg: #050814;
      --card-bg: #111633;
      --card-border: rgba(0,240,255,0.08);
      --card-border-hover: rgba(0,240,255,0.25);
      --shadow-card: 0 8px 32px rgba(0,0,0,0.4);
      --radius-lg: 16px;
      --radius-full: 50px;
      --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
      --spacing-section: 100px;
    }
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }
    html {
      scroll-behavior: smooth;
    }
    body {
      font-family: var(--font-sans);
      background-color: var(--bg);
      color: var(--text);
      line-height: 1.5;
      -webkit-font-smoothing: antialiased;
      -moz-osx-font-smoothing: grayscale;
      overflow-x: hidden;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    a {
      text-decoration: none;
      color: inherit;
      transition: color 0.2s ease;
    }
    button, .btn {
      cursor: pointer;
      font-family: inherit;
      border: none;
      outline: none;
      transition: all 0.2s ease;
    }
    .container {
      max-width: 1280px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 24px;
      padding-right: 24px;
    }
    @media (max-width: 768px) {
      .container {
        padding-left: 16px;
        padding-right: 16px;
      }
      :root {
        --spacing-section: 60px;
      }
    }

    /* 导航 */
    .navbar {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 50;
      backdrop-filter: blur(12px);
      background-color: rgba(5,8,20,0.7);
      border-bottom: 1px solid rgba(0,240,255,0.08);
      height: 72px;
      display: flex;
      align-items: center;
    }
    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
    }
    .logo {
      font-weight: 700;
      font-size: 28px;
      letter-spacing: -0.5px;
      color: #fff;
      display: flex;
      align-items: center;
      gap: 8px;
    }
    .logo i {
      color: var(--accent);
      font-size: 32px;
    }
    .logo span {
      background: linear-gradient(135deg, #fff 0%, var(--accent) 90%);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
    }
    .nav-menu {
      display: flex;
      align-items: center;
      gap: 32px;
    }
    .nav-menu a {
      font-size: 15px;
      font-weight: 500;
      color: var(--muted);
      transition: color 0.2s;
    }
    .nav-menu a:hover,
    .nav-menu a.active {
      color: var(--accent);
    }
    .btn-primary {
      background-color: var(--accent);
      color: var(--primary);
      padding: 10px 28px;
      border-radius: var(--radius-full);
      font-weight: 700;
      font-size: 14px;
      letter-spacing: 0.3px;
      box-shadow: 0 0 12px rgba(0,240,255,0.3);
      display: inline-flex;
      align-items: center;
      justify-content: center;
    }
    .btn-primary:hover {
      box-shadow: 0 0 28px rgba(0,240,255,0.6);
      transform: translateY(-1px);
    }
    .btn-outline {
      background: transparent;
      border: 1.5px solid var(--accent);
      color: var(--accent);
      padding: 10px 28px;
      border-radius: var(--radius-full);
      font-weight: 700;
      font-size: 14px;
    }
    .btn-outline:hover {
      background: rgba(0,240,255,0.08);
    }
    .mobile-nav {
      display: none;
    }
    @media (max-width: 768px) {
      .desktop-nav {
        display: none;
      }
      .mobile-nav {
        display: flex;
        position: fixed;
        bottom: 0;
        left: 0;
        width: 100%;
        background: rgba(5,8,20,0.9);
        backdrop-filter: blur(20px);
        border-top: 1px solid rgba(0,240,255,0.12);
        justify-content: space-around;
        align-items: center;
        padding: 8px 12px 12px;
        z-index: 50;
        height: 68px;
      }
      .mobile-nav a {
        display: flex;
        flex-direction: column;
        align-items: center;
        font-size: 11px;
        color: var(--muted);
        gap: 4px;
      }
      .mobile-nav a i {
        font-size: 18px;
      }
      .mobile-nav a.active {
        color: var(--accent);
      }
      .mobile-cta {
        background: var(--accent);
        color: var(--primary);
        padding: 8px 20px;
        border-radius: 30px;
        font-weight: 700;
        font-size: 12px;
        box-shadow: 0 0 16px rgba(0,240,255,0.5);
      }
      .navbar {
        height: auto;
        background: transparent;
        backdrop-filter: none;
        border-bottom: none;
      }
      .logo {
        font-size: 22px;
      }
    }

    /* Hero */
    .hero {
      min-height: 100vh;
      display: flex;
      align-items: center;
      justify-content: center;
      text-align: center;
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      position: relative;
      padding: 120px 24px 80px;
    }
    .hero::before {
      content: '';
      position: absolute;
      inset: 0;
      background: radial-gradient(circle at 30% 40%, rgba(0,240,255,0.15) 0%, rgba(5,8,20,0.85) 80%);
    }
    .hero-content {
      position: relative;
      z-index: 2;
      max-width: 800px;
      margin: 0 auto;
    }
    .hero h1 {
      font-size: 48px;
      font-weight: 700;
      line-height: 1.2;
      letter-spacing: -0.5px;
      background: linear-gradient(to right, #fff, var(--accent));
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
      margin-bottom: 24px;
    }
    .hero p {
      font-size: 18px;
      color: var(--muted);
      margin-bottom: 40px;
      max-width: 600px;
      margin-left: auto;
      margin-right: auto;
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      justify-content: center;
      flex-wrap: wrap;
    }
    @media (max-width: 768px) {
      .hero h1 {
        font-size: 32px;
      }
      .hero p {
        font-size: 16px;
      }
      .hero {
        padding-top: 100px;
        padding-bottom: 100px;
      }
    }

    /* 通用板块标题 */
    .section-title {
      font-size: 36px;
      font-weight: 700;
      line-height: 1.2;
      margin-bottom: 16px;
      color: #fff;
    }
    .section-sub {
      color: var(--muted);
      font-size: 16px;
      margin-bottom: 48px;
    }
    @media (max-width: 768px) {
      .section-title {
        font-size: 28px;
      }
    }

    /* 卡片网格 */
    .card-grid {
      display: grid;
      gap: 24px;
    }
    .card {
      background: var(--card-bg);
      border: 1px solid var(--card-border);
      border-radius: var(--radius-lg);
      padding: 32px;
      box-shadow: var(--shadow-card);
      transition: transform 0.25s ease, border-color 0.25s;
    }
    .card:hover {
      transform: translateY(-4px);
      border-color: var(--card-border-hover);
    }
    .card-icon {
      font-size: 32px;
      color: var(--accent);
      margin-bottom: 20px;
      transition: transform 0.2s;
    }
    .card:hover .card-icon {
      transform: scale(1.1);
      text-shadow: 0 0 12px rgba(0,240,255,0.6);
    }
    .card h3 {
      font-size: 24px;
      font-weight: 600;
      margin-bottom: 12px;
      color: #fff;
    }
    .card p {
      color: var(--muted);
      font-size: 14px;
      line-height: 1.6;
    }

    /* 服务卡片 */
    .service-img {
      width: 100%;
      height: 140px;
      object-fit: cover;
      border-radius: 12px;
      margin-bottom: 20px;
      background: #0f142e;
    }
    .tag {
      display: inline-block;
      background: rgba(0,240,255,0.1);
      color: var(--accent);
      font-size: 12px;
      padding: 4px 12px;
      border-radius: 20px;
      margin-bottom: 10px;
    }

    /* 数据引擎 */
    .stat-grid {
      display: grid;
      grid-template-columns: repeat(4,1fr);
      gap: 32px;
      text-align: center;
    }
    .stat-number {
      font-size: 48px;
      font-weight: 700;
      color: var(--accent);
      line-height: 1.2;
    }
    .stat-label {
      color: var(--muted);
      font-size: 14px;
      margin-top: 8px;
    }
    @media (max-width: 768px) {
      .stat-grid {
        grid-template-columns: repeat(2,1fr);
      }
    }

    /* 合作伙伴logo墙 */
    .logo-wall {
      display: flex;
      flex-wrap: wrap;
      justify-content: center;
      align-items: center;
      gap: 40px;
      filter: grayscale(1);
      opacity: 0.7;
    }
    .logo-wall img {
      height: 40px;
      transition: filter 0.2s;
    }
    .logo-wall img:hover {
      filter: grayscale(0);
      opacity: 1;
    }

    /* FAQ */
    .faq-item {
      border-bottom: 1px solid rgba(255,255,255,0.06);
    }
    .faq-question {
      width: 100%;
      background: transparent;
      color: #fff;
      font-size: 16px;
      font-weight: 600;
      padding: 20px 0;
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
      border: none;
      text-align: left;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      color: var(--muted);
      font-size: 14px;
      padding-bottom: 0;
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      padding-bottom: 20px;
    }
    .faq-item.active .faq-icon {
      transform: rotate(45deg);
    }
    .faq-icon {
      font-size: 20px;
      color: var(--accent);
      transition: transform 0.3s;
    }

    /* CTA Banner */
    .cta-banner {
      background: linear-gradient(135deg, #0a0e27 0%, #111f3a 100%);
      position: relative;
      overflow: hidden;
      border-radius: 32px;
      padding: 80px 24px;
      text-align: center;
    }
    .cta-banner::after {
      content: '';
      position: absolute;
      top: -50%;
      right: -20%;
      width: 500px;
      height: 500px;
      background: radial-gradient(circle, rgba(0,240,255,0.15) 0%, transparent 70%);
      border-radius: 50%;
    }
    .cta-banner h2 {
      font-size: 36px;
      font-weight: 700;
      color: #fff;
      position: relative;
      z-index: 2;
    }
    .cta-banner p {
      color: var(--muted);
      margin: 16px 0 32px;
      position: relative;
      z-index: 2;
    }

    /* Footer */
    .footer {
      background: #02040f;
      padding: 60px 0 24px;
      margin-top: 80px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
      margin-bottom: 40px;
    }
    .footer h4 {
      color: #fff;
      margin-bottom: 16px;
    }
    .footer a, .footer p {
      color: var(--muted);
      font-size: 14px;
    }
    .footer a:hover {
      color: var(--accent);
    }
    .copyright {
      border-top: 1px solid rgba(255,255,255,0.06);
      padding-top: 24px;
      text-align: center;
      color: var(--muted);
      font-size: 13px;
    }
    @media (max-width: 768px) {
      .footer-grid {
        grid-template-columns: 1fr;
      }
    }