/* roulang page: index */
:root {
      --primary: #0A1F3F;
      --accent: #E8A317;
      --accent-hover: #C88914;
      --bg: #F8FAFC;
      --card-bg: #FFFFFF;
      --text-main: #1E293B;
      --text-muted: #64748B;
      --border: #E2E8F0;
      --radius-md: 12px;
      --radius-btn: 8px;
      --shadow-sm: 0 1px 3px rgba(10,31,63,0.08), 0 4px 12px rgba(10,31,63,0.04);
      --shadow-hover: 0 8px 24px rgba(10,31,63,0.12);
      --font-sans: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", system-ui, -apple-system, 'Segoe UI', Roboto, 'Inter', sans-serif;
      --transition: 0.25s ease;
      --container-width: 1200px;
    }

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

    body {
      font-family: var(--font-sans);
      background-color: var(--bg);
      color: var(--text-main);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
    }

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

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

    a {
      text-decoration: none;
      color: inherit;
    }

    /* 导航 fix */
    #nav {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 72px;
      background: rgba(255,255,255,0.95);
      backdrop-filter: blur(8px);
      border-bottom: 1px solid var(--border);
      z-index: 100;
      display: flex;
      align-items: center;
    }

    .nav-container {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
      max-width: var(--container-width);
      margin: 0 auto;
      padding: 0 24px;
    }

    .logo {
      font-size: 24px;
      font-weight: 700;
      color: var(--primary);
      display: flex;
      align-items: center;
      gap: 10px;
    }

    .logo::after {
      content: '';
      display: inline-block;
      width: 18px;
      height: 18px;
      background: var(--accent);
      transform: rotate(45deg);
      margin-left: 4px;
      border-radius: 2px;
    }

    .nav-links {
      display: flex;
      gap: 32px;
      align-items: center;
      list-style: none;
    }

    .nav-links a {
      font-size: 15px;
      font-weight: 500;
      color: var(--text-muted);
      position: relative;
      padding-bottom: 6px;
      transition: color var(--transition);
    }

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

    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--accent);
      transition: width var(--transition);
    }

    .nav-links a:hover::after {
      width: 100%;
    }

    .burger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
      background: transparent;
      border: none;
    }

    .burger span {
      width: 26px;
      height: 2.5px;
      background-color: var(--primary);
      border-radius: 4px;
      transition: 0.3s;
    }

    .mobile-menu {
      display: none;
      position: fixed;
      top: 72px;
      left: 0;
      width: 100%;
      background: white;
      flex-direction: column;
      border-bottom: 1px solid var(--border);
      box-shadow: var(--shadow-sm);
      z-index: 99;
    }

    .mobile-menu a {
      padding: 16px 24px;
      border-bottom: 1px solid var(--border);
      font-weight: 500;
      color: var(--text-main);
    }

    /* 区块样式 */
    section {
      padding: 100px 0;
      scroll-margin-top: 72px;
    }

    .bg-primary-section {
      background-color: var(--primary);
      color: white;
    }

    .bg-light-gray {
      background-color: #F1F5F9;
    }

    h1 {
      font-size: 48px;
      line-height: 1.2;
      font-weight: 700;
      color: var(--primary);
      margin-bottom: 20px;
    }

    h2 {
      font-size: 36px;
      line-height: 1.3;
      font-weight: 700;
      margin-bottom: 48px;
      text-align: center;
      color: var(--primary);
    }

    h3 {
      font-size: 22px;
      font-weight: 600;
      line-height: 1.4;
    }

    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 16px;
      letter-spacing: 0.5px;
      padding: 14px 32px;
      transition: all 0.2s ease;
      cursor: pointer;
      border: none;
    }

    .btn-primary {
      background: var(--accent);
      color: var(--primary);
    }

    .btn-primary:hover {
      background: var(--accent-hover);
    }

    .btn-outline {
      background: transparent;
      border: 2px solid var(--primary);
      color: var(--primary);
    }

    .btn-outline:hover {
      background: var(--primary);
      color: white;
    }

    .btn-white {
      background: white;
      color: var(--primary);
      border: 2px solid white;
    }

    .btn-white:hover {
      background: transparent;
      color: white;
    }

    .card {
      background: var(--card-bg);
      border-radius: var(--radius-md);
      box-shadow: var(--shadow-sm);
      transition: all var(--transition);
      padding: 32px;
    }

    .card:hover {
      box-shadow: var(--shadow-hover);
      transform: translateY(-4px);
    }

    /* Hero */
    .hero-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 60px;
      align-items: center;
      min-height: 85vh;
    }

    .hero-left p {
      font-size: 18px;
      color: var(--text-muted);
      margin-bottom: 32px;
    }

    .hero-image img {
      border-radius: 16px;
      box-shadow: 0 10px 30px rgba(0,0,0,0.05);
    }

    .btn-group {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }

    /* 服务卡片水平布局 */
    .services-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }

    .service-card {
      display: flex;
      align-items: flex-start;
      gap: 24px;
      background: var(--card-bg);
      border-radius: var(--radius-md);
      box-shadow: var(--shadow-sm);
      padding: 32px;
      transition: all var(--transition);
    }

    .service-card:hover {
      box-shadow: var(--shadow-hover);
      transform: translateY(-4px);
    }

    .service-icon {
      width: 64px;
      height: 64px;
      background: #F1F5F9;
      border-radius: 12px;
      display: flex;
      align-items: center;
      justify-content: center;
      color: var(--accent);
      font-size: 30px;
      flex-shrink: 0;
    }

    .service-text h3 {
      margin-bottom: 8px;
      font-size: 20px;
    }

    .service-text p {
      font-size: 15px;
      color: var(--text-muted);
      margin-bottom: 12px;
    }

    .link-more {
      color: var(--text-muted);
      font-weight: 500;
      font-size: 14px;
      transition: color 0.2s;
    }

    .link-more:hover {
      color: var(--accent);
      text-decoration: underline;
    }

    /* 数据区 */
    .stats-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);
    }

    .stat-label {
      font-size: 16px;
      opacity: 0.9;
    }

    /* 案例非对称 */
    .cases-grid {
      display: grid;
      grid-template-columns: 2fr 1fr;
      gap: 24px;
      margin-bottom: 24px;
    }

    .cases-row {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 24px;
    }

    .case-card {
      position: relative;
      border-radius: var(--radius-md);
      overflow: hidden;
      height: 260px;
      background-size: cover;
      background-position: center;
      box-shadow: var(--shadow-sm);
      transition: all 0.3s;
    }

    .case-card:hover {
      transform: scale(1.02);
    }

    .case-overlay {
      position: absolute;
      inset: 0;
      background: linear-gradient(to top, rgba(10,31,63,0.8), transparent);
      display: flex;
      flex-direction: column;
      justify-content: flex-end;
      padding: 24px;
      color: white;
    }

    .case-tag {
      background: var(--accent);
      color: var(--primary);
      padding: 4px 12px;
      border-radius: 20px;
      font-size: 12px;
      font-weight: 600;
      align-self: flex-start;
      margin-bottom: 8px;
    }

    /* 流程 */
    .process-steps {
      display: flex;
      justify-content: space-between;
      align-items: flex-start;
      position: relative;
    }

    .step-item {
      display: flex;
      flex-direction: column;
      align-items: center;
      width: 180px;
      text-align: center;
    }

    .step-circle {
      width: 56px;
      height: 56px;
      border-radius: 50%;
      background: white;
      border: 2px solid var(--accent);
      color: var(--primary);
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 700;
      font-size: 20px;
      margin-bottom: 16px;
      position: relative;
      z-index: 2;
    }

    .step-line {
      position: absolute;
      top: 28px;
      left: 10%;
      width: 80%;
      height: 2px;
      border-top: 2px dashed var(--accent);
      z-index: 1;
    }

    /* FAQ */
    .faq-item {
      background: white;
      border-radius: var(--radius-md);
      margin-bottom: 12px;
      padding: 18px 24px;
      box-shadow: 0 1px 4px rgba(0,0,0,0.02);
      cursor: pointer;
    }

    .faq-question {
      display: flex;
      justify-content: space-between;
      font-weight: 600;
      font-size: 16px;
    }

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      color: var(--text-muted);
      font-size: 15px;
      margin-top: 8px;
    }

    .faq-item.active .faq-answer {
      max-height: 200px;
    }

    /* footer */
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
      color: #CBD5E1;
    }

    .footer-logo {
      font-size: 24px;
      font-weight: 700;
      color: white;
    }

    @media (max-width: 1024px) {
      .hero-grid {
        grid-template-columns: 1fr;
        text-align: center;
        gap: 40px;
      }
      .services-grid {
        grid-template-columns: 1fr 1fr;
      }
      .stats-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .cases-grid, .cases-row {
        grid-template-columns: 1fr;
      }
      .process-steps {
        flex-wrap: wrap;
        justify-content: center;
        gap: 24px;
      }
      .step-line {
        display: none;
      }
    }

    @media (max-width: 768px) {
      h1 {
        font-size: 36px;
      }
      h2 {
        font-size: 28px;
      }
      .nav-links {
        display: none;
      }
      .burger {
        display: flex;
      }
      .services-grid {
        grid-template-columns: 1fr;
      }
      .footer-grid {
        grid-template-columns: 1fr;
      }
    }