/* roulang page: index */
:root {
      --primary: #1A5FDC;
      --primary-hover: #154DB5;
      --primary-soft: rgba(26,95,220,0.08);
      --accent: #F5A623;
      --accent-hover: #E8961A;
      --accent-glow: rgba(245,166,35,0.3);
      --bg: #FAFBFD;
      --surface: #FFFFFF;
      --bg-alt: #F2F5FA;
      --text-primary: #0B1E3C;
      --text-body: #3A4A62;
      --text-muted: #7B8BA0;
      --border: #E8EDF4;
      --border-light: #ECF0F5;
      --radius-card: 16px;
      --radius-btn: 10px;
      --radius-cta: 12px;
      --shadow-card: 0 4px 20px rgba(26,95,220,0.06);
      --shadow-hover: 0 10px 30px rgba(26,95,220,0.12);
      --font-stack: 'PingFang SC', 'Microsoft YaHei', 'Hiragino Sans GB', system-ui, -apple-system, sans-serif;
      --max-width: 1280px;
      --section-gap: 100px;
      --card-gap: 24px;
      --transition: 0.25s ease;
    }
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }
    html {
      scroll-behavior: smooth;
    }
    body {
      font-family: var(--font-stack);
      background: var(--bg);
      color: var(--text-body);
      line-height: 1.7;
      font-weight: 400;
      -webkit-font-smoothing: antialiased;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    a {
      text-decoration: none;
      color: inherit;
      transition: var(--transition);
    }
    button, .btn {
      cursor: pointer;
      font-family: inherit;
      border: none;
      background: none;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      font-weight: 600;
      transition: var(--transition);
      outline: none;
    }
    .container {
      width: 100%;
      max-width: var(--max-width);
      margin-left: auto;
      margin-right: auto;
      padding-left: 24px;
      padding-right: 24px;
    }
    /* 导航 */
    .header {
      position: sticky;
      top: 0;
      z-index: 50;
      background: rgba(255,255,255,0.92);
      backdrop-filter: blur(10px);
      border-bottom: 1px solid var(--border-light);
      padding: 12px 0;
    }
    .nav {
      display: flex;
      align-items: center;
      justify-content: space-between;
      flex-wrap: wrap;
    }
    .logo {
      font-size: 1.5rem;
      font-weight: 700;
      color: var(--text-primary);
      letter-spacing: -0.2px;
      white-space: nowrap;
    }
    .logo span {
      color: var(--primary);
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 8px;
      flex-wrap: wrap;
    }
    .nav-link {
      padding: 8px 18px;
      border-radius: 40px;
      font-weight: 500;
      font-size: 0.95rem;
      color: var(--text-body);
      transition: var(--transition);
    }
    .nav-link:hover {
      background: var(--primary-soft);
      color: var(--primary);
    }
    .mobile-nav {
      display: none;
    }
    /* Hero */
    .hero {
      padding: 70px 0 80px;
    }
    .hero-grid {
      display: flex;
      align-items: center;
      gap: 60px;
    }
    .hero-content {
      flex: 1 1 50%;
    }
    .hero-image {
      flex: 1 1 50%;
    }
    .hero-image img {
      border-radius: 20px;
      box-shadow: var(--shadow-card);
      width: 100%;
    }
    h1 {
      font-size: 2.8rem;
      font-weight: 700;
      color: var(--text-primary);
      line-height: 1.3;
      margin-bottom: 18px;
      letter-spacing: -0.3px;
    }
    .hero-sub {
      font-size: 1.1rem;
      color: var(--text-body);
      margin-bottom: 32px;
      max-width: 540px;
    }
    .btn-group {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .btn-primary {
      background: var(--primary);
      color: white;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
    }
    .btn-primary:hover {
      background: var(--primary-hover);
      box-shadow: 0 4px 12px rgba(26,95,220,0.25);
    }
    .btn-outline {
      background: transparent;
      border: 2px solid var(--primary);
      color: var(--primary);
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
    }
    .btn-outline:hover {
      background: var(--primary-soft);
    }
    .btn-cta {
      background: linear-gradient(135deg, var(--accent) 0%, var(--accent-hover) 100%);
      color: white;
      padding: 16px 36px;
      border-radius: var(--radius-cta);
      font-weight: 600;
      box-shadow: 0 8px 18px rgba(245,166,35,0.3);
    }
    .btn-cta:hover {
      box-shadow: 0 12px 24px rgba(245,166,35,0.4);
      transform: translateY(-1px);
    }
    /* 通用板块 */
    .section {
      padding: var(--section-gap) 0;
    }
    .section-alt {
      background: var(--bg-alt);
    }
    h2 {
      font-size: 2.2rem;
      font-weight: 700;
      color: var(--text-primary);
      margin-bottom: 16px;
      letter-spacing: -0.2px;
    }
    .section-desc {
      color: var(--text-muted);
      font-size: 1.05rem;
      margin-bottom: 48px;
    }
    .grid-3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: var(--card-gap);
    }
    .card {
      background: var(--surface);
      border: 1px solid var(--border);
      border-radius: var(--radius-card);
      padding: 28px;
      box-shadow: var(--shadow-card);
      transition: var(--transition);
    }
    .card:hover {
      box-shadow: var(--shadow-hover);
      transform: translateY(-4px);
    }
    .icon-circle {
      width: 44px;
      height: 44px;
      background: var(--primary-soft);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      margin-bottom: 20px;
      color: var(--primary);
      font-size: 1.3rem;
    }
    h3 {
      font-size: 1.25rem;
      font-weight: 600;
      color: var(--text-primary);
      margin-bottom: 8px;
    }
    h4 {
      font-size: 1.1rem;
      font-weight: 600;
      color: var(--text-primary);
      margin-bottom: 6px;
    }
    /* 服务特色不等高 */
    .services-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: var(--card-gap);
    }
    .service-card {
      background: var(--surface);
      border: 1px solid var(--border);
      border-radius: var(--radius-card);
      padding: 32px 24px 28px;
      box-shadow: var(--shadow-card);
      transition: var(--transition);
      display: flex;
      flex-direction: column;
    }
    .service-card.featured {
      border-top: 4px solid var(--accent);
      transform: scale(1.02);
      box-shadow: 0 8px 25px rgba(26,95,220,0.08);
    }
    .service-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-hover);
    }
    /* 数据条 */
    .stats-bar {
      display: flex;
      justify-content: space-around;
      flex-wrap: wrap;
      text-align: center;
      gap: 30px;
    }
    .stat-number {
      font-size: 2.5rem;
      font-weight: 700;
      color: var(--primary);
      line-height: 1.2;
    }
    .stat-label {
      color: var(--text-muted);
      font-weight: 500;
    }
    /* 案例网格 */
    .cases-grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 28px;
    }
    .case-card {
      background: var(--surface);
      border-radius: var(--radius-card);
      overflow: hidden;
      display: flex;
      border: 1px solid var(--border-light);
      box-shadow: var(--shadow-card);
      transition: var(--transition);
    }
    .case-card:hover {
      box-shadow: var(--shadow-hover);
      transform: translateY(-3px);
    }
    .case-img {
      width: 45%;
      object-fit: cover;
    }
    .case-info {
      padding: 24px;
      display: flex;
      flex-direction: column;
      justify-content: center;
    }
    .badge {
      display: inline-block;
      background: rgba(245,166,35,0.12);
      color: var(--accent);
      font-weight: 600;
      font-size: 0.8rem;
      padding: 4px 12px;
      border-radius: 20px;
      margin-bottom: 10px;
    }
    /* 流程 */
    .process-steps {
      display: flex;
      flex-direction: column;
      gap: 32px;
      position: relative;
      padding-left: 40px;
    }
    .process-steps::before {
      content: '';
      position: absolute;
      left: 19px;
      top: 8px;
      bottom: 8px;
      width: 2px;
      background: var(--border);
    }
    .step {
      position: relative;
    }
    .step-circle {
      width: 40px;
      height: 40px;
      background: var(--primary);
      color: white;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 700;
      position: absolute;
      left: -40px;
      top: 0;
      box-shadow: 0 4px 10px rgba(26,95,220,0.2);
    }
    /* FAQ */
    .faq-list {
      display: flex;
      flex-direction: column;
      gap: 8px;
    }
    .faq-item {
      border-bottom: 1px solid var(--border-light);
    }
    .faq-question {
      width: 100%;
      text-align: left;
      padding: 18px 8px;
      font-weight: 600;
      color: var(--text-primary);
      display: flex;
      justify-content: space-between;
      align-items: center;
      background: transparent;
      font-size: 1rem;
      border-left: 3px solid transparent;
      transition: var(--transition);
    }
    .faq-item.active .faq-question {
      border-left-color: var(--accent);
      background: #F9FBFE;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease;
      padding: 0 12px;
      color: var(--text-body);
    }
    .faq-item.active .faq-answer {
      max-height: 160px;
      padding-bottom: 16px;
    }
    /* CTA 横幅 */
    .cta-band {
      background: var(--primary);
      color: white;
      text-align: center;
      padding: 70px 20px;
      border-radius: 24px;
      margin: 0 24px;
    }
    .cta-band h2 {
      color: white;
    }
    .footer {
      background: #0B1E3C;
      color: #C0CCDA;
      padding: 60px 0 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
    }
    .footer-logo {
      font-size: 1.3rem;
      font-weight: 700;
      color: white;
      margin-bottom: 12px;
    }
    .footer a {
      color: #C0CCDA;
      display: block;
      margin-bottom: 8px;
    }
    .footer a:hover {
      color: white;
    }
    .copyright {
      border-top: 1px solid rgba(255,255,255,0.08);
      margin-top: 40px;
      padding-top: 24px;
      text-align: center;
      font-size: 0.9rem;
    }
    @media (max-width: 1024px) {
      .hero-grid {
        gap: 40px;
      }
      .grid-3, .services-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .cases-grid {
        grid-template-columns: 1fr;
      }
    }
    @media (max-width: 768px) {
      :root {
        --section-gap: 60px;
      }
      h1 {
        font-size: 2rem;
      }
      .nav-links {
        display: none;
      }
      .mobile-nav {
        display: flex;
        position: fixed;
        bottom: 0;
        left: 0;
        right: 0;
        background: white;
        border-top: 1px solid var(--border);
        justify-content: space-around;
        padding: 10px 12px;
        z-index: 60;
        box-shadow: 0 -4px 15px rgba(0,0,0,0.04);
      }
      .mobile-nav a {
        font-size: 0.75rem;
        display: flex;
        flex-direction: column;
        align-items: center;
        color: var(--text-muted);
        font-weight: 500;
      }
      .mobile-nav a.active {
        color: var(--primary);
      }
      .hero-grid {
        flex-direction: column;
      }
      .grid-3, .services-grid, .footer-grid {
        grid-template-columns: 1fr;
      }
      .stats-bar {
        gap: 24px;
      }
      .process-steps {
        padding-left: 32px;
      }
      .cta-band {
        margin: 0 12px;
        padding: 50px 16px;
      }
    }