/* roulang page: index */
:root {
      --primary: #1A5FDC;
      --primary-hover: #1349B0;
      --primary-active: #0E3A8C;
      --accent-green: #00B578;
      --accent-green-hover: #009A62;
      --accent-orange: #FF6A3D;
      --accent-orange-hover: #E55A2B;
      --bg: #F5F6FA;
      --bg-card: #FFFFFF;
      --bg-secondary: #EEF0F5;
      --bg-dark: #0F172A;
      --text-main: #1F2329;
      --text-secondary: #5A6270;
      --text-light: #86909C;
      --text-white: #FFFFFF;
      --success: #00B578;
      --warning: #FF9F0A;
      --error: #FA5151;
      --shadow-card: 0 2px 8px rgba(0,0,0,0.04);
      --shadow-card-hover: 0 4px 20px rgba(0,0,0,0.06), 0 1px 4px rgba(0,0,0,0.04);
      --shadow-nav: 0 1px 0 rgba(0,0,0,0.04), 0 2px 8px rgba(0,0,0,0.03);
      --shadow-btn: 0 4px 12px rgba(26,95,220,0.25);
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-input: 24px;
      --font-stack: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
      --max-width: 1200px;
      --padding-section: 100px;
      --gap-card: 24px;
      --space-card: 32px;
    }

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

    body {
      font-family: var(--font-stack);
      background-color: var(--bg);
      color: var(--text-main);
      line-height: 1.6;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
      -moz-osx-font-smoothing: grayscale;
    }

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

    a {
      text-decoration: none;
      color: inherit;
      transition: color 0.2s ease;
    }

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

    button, .button {
      cursor: pointer;
      font-family: inherit;
      border: none;
      background: none;
    }

    /* 导航 */
    .header {
      position: sticky;
      top: 0;
      left: 0;
      width: 100%;
      background: var(--bg-card);
      box-shadow: var(--shadow-nav);
      z-index: 1000;
      height: 72px;
      display: flex;
      align-items: center;
      backdrop-filter: blur(8px);
      background: rgba(255,255,255,0.96);
    }

    .header .container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 100%;
    }

    .logo {
      font-size: 22px;
      font-weight: 700;
      color: var(--primary);
      display: flex;
      align-items: center;
      gap: 8px;
      white-space: nowrap;
    }

    .logo-icon {
      width: 24px;
      height: 24px;
      display: flex;
      align-items: center;
      justify-content: center;
    }

    .nav-menu {
      display: flex;
      align-items: center;
      gap: 36px;
    }

    .nav-link {
      font-size: 16px;
      font-weight: 500;
      color: var(--text-main);
      padding: 8px 0;
      border-bottom: 2px solid transparent;
      transition: color 0.2s, border-color 0.2s;
      white-space: nowrap;
    }

    .nav-link:hover, .nav-link.active {
      color: var(--primary);
      border-bottom-color: var(--primary);
    }

    .btn-primary {
      background: var(--primary);
      color: var(--text-white);
      padding: 10px 22px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 15px;
      transition: background 0.2s, box-shadow 0.2s;
      display: inline-block;
      text-align: center;
      white-space: nowrap;
    }

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

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

    .btn-outline {
      background: transparent;
      border: 1.5px solid var(--primary);
      color: var(--primary);
      padding: 10px 22px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 15px;
      transition: background 0.2s, color 0.2s;
      display: inline-block;
    }

    .btn-outline:hover {
      background: rgba(26,95,220,0.05);
    }

    .btn-white {
      background: white;
      color: var(--primary);
      padding: 14px 36px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 16px;
      transition: background 0.2s, box-shadow 0.2s;
      display: inline-block;
    }

    .btn-white:hover {
      background: #F0F4FF;
      box-shadow: var(--shadow-btn);
    }

    .btn-ghost-light {
      background: transparent;
      border: 1.5px solid white;
      color: white;
      padding: 14px 36px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 16px;
      transition: background 0.2s;
    }

    .btn-ghost-light:hover {
      background: rgba(255,255,255,0.1);
    }

    .hamburger {
      display: none;
      flex-direction: column;
      gap: 6px;
      cursor: pointer;
      background: none;
      border: none;
      padding: 4px;
    }

    .hamburger span {
      display: block;
      width: 26px;
      height: 2px;
      background: var(--text-main);
      border-radius: 2px;
      transition: transform 0.3s, opacity 0.3s;
    }

    .mobile-menu {
      display: none;
      position: fixed;
      top: 72px;
      left: 0;
      width: 100%;
      background: var(--bg-card);
      box-shadow: 0 8px 20px rgba(0,0,0,0.06);
      flex-direction: column;
      padding: 24px;
      gap: 24px;
      z-index: 999;
      transform: translateY(-10px);
      opacity: 0;
      pointer-events: none;
      transition: all 0.25s ease;
    }

    .mobile-menu.open {
      display: flex;
      transform: translateY(0);
      opacity: 1;
      pointer-events: auto;
    }

    .mobile-menu .nav-link {
      font-size: 18px;
      padding: 12px 0;
      border-bottom: none;
    }

    /* 板块通用 */
    section {
      padding: var(--padding-section) 0;
    }

    .section-title {
      font-size: 28px;
      font-weight: 700;
      color: var(--text-main);
      margin-bottom: 16px;
      line-height: 1.4;
    }

    .section-subtitle {
      font-size: 16px;
      color: var(--text-secondary);
      margin-bottom: 48px;
      max-width: 700px;
    }

    .text-center {
      text-align: center;
    }

    .mx-auto {
      margin-left: auto;
      margin-right: auto;
    }

    /* Hero */
    #hero {
      background: var(--bg-card);
      padding: 120px 0;
    }

    .hero-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 60px;
      align-items: center;
    }

    .hero-content h1 {
      font-size: 36px;
      font-weight: 700;
      line-height: 1.3;
      color: var(--text-main);
      margin-bottom: 16px;
    }

    .hero-content p {
      font-size: 16px;
      color: var(--text-secondary);
      margin-bottom: 32px;
      line-height: 1.6;
      max-width: 480px;
    }

    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }

    .hero-image {
      background: #eef3fc;
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-card);
      display: flex;
      align-items: center;
      justify-content: center;
    }

    .hero-image img {
      width: 100%;
      height: auto;
      object-fit: cover;
      border-radius: var(--radius-card);
    }

    /* 核心优势 */
    .features-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: var(--gap-card);
      margin-top: 16px;
    }

    .feature-card {
      background: var(--bg-card);
      padding: var(--space-card);
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-card);
      transition: box-shadow 0.2s, transform 0.2s;
    }

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

    .feature-icon {
      width: 32px;
      height: 32px;
      margin-bottom: 20px;
      color: var(--primary);
      font-size: 32px;
      line-height: 1;
    }

    .feature-card h3 {
      font-size: 20px;
      font-weight: 600;
      margin-bottom: 8px;
      color: var(--text-main);
    }

    .feature-card p {
      font-size: 14px;
      color: var(--text-secondary);
      line-height: 1.5;
    }

    /* 服务产品 */
    .services-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: var(--gap-card);
    }

    .service-card {
      background: var(--bg-card);
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-card);
      overflow: hidden;
      transition: box-shadow 0.2s, transform 0.2s;
    }

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

    .service-img {
      height: 180px;
      overflow: hidden;
    }

    .service-img img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      transition: transform 0.3s ease;
    }

    .service-card:hover .service-img img {
      transform: scale(1.03);
    }

    .service-body {
      padding: 24px;
    }

    .service-body h3 {
      font-size: 20px;
      font-weight: 600;
      margin-bottom: 8px;
      color: var(--text-main);
    }

    .service-body p {
      font-size: 14px;
      color: var(--text-secondary);
      margin-bottom: 16px;
    }

    .service-link {
      font-size: 14px;
      font-weight: 500;
      color: var(--primary);
      display: inline-flex;
      align-items: center;
      gap: 4px;
      transition: gap 0.2s;
    }

    .service-link:hover {
      text-decoration: underline;
    }

    /* 数据实力 */
    #stats {
      background: var(--bg-dark);
      padding: 80px 0;
    }

    .stats-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 40px;
      text-align: center;
    }

    .stat-item .stat-number {
      font-size: 40px;
      font-weight: 700;
      color: white;
      line-height: 1.2;
    }

    .stat-item .stat-unit {
      font-size: 20px;
      font-weight: 400;
      color: var(--text-light);
    }

    .stat-label {
      font-size: 14px;
      color: var(--text-light);
      margin-top: 8px;
    }

    /* 案例展示 */
    .cases-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: var(--gap-card);
    }

    .case-card {
      background: var(--bg-card);
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-card);
      overflow: hidden;
      transition: box-shadow 0.2s;
    }

    .case-card:hover {
      box-shadow: var(--shadow-card-hover);
    }

    .case-img {
      height: 200px;
      overflow: hidden;
    }

    .case-img img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      transition: transform 0.3s;
    }

    .case-card:hover .case-img img {
      transform: scale(1.03);
    }

    .case-body {
      padding: 24px;
    }

    .case-body h3 {
      font-size: 20px;
      font-weight: 600;
      margin-bottom: 8px;
    }

    .case-body p {
      font-size: 14px;
      color: var(--text-secondary);
      margin-bottom: 12px;
    }

    .badge {
      display: inline-block;
      background: rgba(0,181,120,0.1);
      color: var(--accent-green);
      font-size: 12px;
      font-weight: 500;
      padding: 4px 10px;
      border-radius: 4px;
    }

    /* 流程 */
    #process {
      background: var(--bg-secondary);
    }

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

    .step-item {
      flex: 1;
      text-align: center;
      position: relative;
      padding: 0 16px;
    }

    .step-circle {
      width: 40px;
      height: 40px;
      background: var(--primary);
      color: white;
      font-weight: 700;
      font-size: 16px;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      margin: 0 auto 20px;
      position: relative;
      z-index: 2;
    }

    .step-line {
      position: absolute;
      top: 20px;
      left: calc(50% + 28px);
      width: calc(100% - 56px);
      height: 2px;
      background: #CBD0D8;
      z-index: 1;
    }

    .step-item:last-child .step-line {
      display: none;
    }

    .step-item h3 {
      font-size: 20px;
      font-weight: 600;
      margin-bottom: 8px;
      color: var(--text-main);
    }

    .step-item p {
      font-size: 14px;
      color: var(--text-secondary);
    }

    /* FAQ */
    .faq-container {
      max-width: 800px;
      margin: 0 auto;
    }

    .faq-item {
      background: var(--bg-card);
      border-radius: var(--radius-card);
      margin-bottom: 16px;
      box-shadow: var(--shadow-card);
      overflow: hidden;
    }

    .faq-question {
      width: 100%;
      padding: 20px 24px;
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-size: 18px;
      font-weight: 600;
      background: white;
      border: none;
      cursor: pointer;
      text-align: left;
      color: var(--text-main);
    }

    .faq-icon {
      font-size: 20px;
      font-weight: 400;
      color: var(--primary);
      transition: transform 0.3s;
    }

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      background: var(--bg);
    }

    .faq-answer-content {
      padding: 20px 24px;
      font-size: 16px;
      color: var(--text-secondary);
    }

    .faq-item.active .faq-answer {
      max-height: 300px;
    }

    .faq-item.active .faq-icon {
      transform: rotate(45deg);
    }

    /* CTA */
    #cta {
      background: linear-gradient(135deg, var(--primary), var(--primary-hover));
      padding: 80px 0;
      text-align: center;
    }

    #cta h2 {
      font-size: 28px;
      font-weight: 700;
      color: white;
      margin-bottom: 12px;
    }

    #cta p {
      font-size: 16px;
      color: rgba(255,255,255,0.85);
      margin-bottom: 32px;
    }

    .cta-buttons {
      display: flex;
      gap: 16px;
      justify-content: center;
      flex-wrap: wrap;
    }

    /* Footer */
    #footer {
      background: var(--bg-dark);
      color: var(--text-light);
      padding: 60px 24px;
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
      max-width: var(--max-width);
      margin: 0 auto 40px;
    }

    .footer-logo {
      font-size: 20px;
      font-weight: 700;
      color: white;
      margin-bottom: 12px;
    }

    .footer-desc {
      font-size: 14px;
      color: var(--text-light);
      margin-bottom: 16px;
    }

    .footer-col h4 {
      font-size: 16px;
      font-weight: 600;
      color: white;
      margin-bottom: 20px;
    }

    .footer-col a {
      display: block;
      font-size: 14px;
      color: var(--text-light);
      margin-bottom: 12px;
      transition: color 0.2s;
    }

    .footer-col a:hover {
      color: white;
    }

    .footer-divider {
      border-top: 1px solid #1E293B;
      max-width: var(--max-width);
      margin: 0 auto;
      padding-top: 24px;
      font-size: 12px;
      color: var(--text-light);
    }

    /* 响应式 */
    @media (max-width: 992px) {
      .hero-grid {
        grid-template-columns: 1fr;
        gap: 40px;
      }
      .services-grid, .cases-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .footer-grid {
        grid-template-columns: 1fr 1fr;
      }
    }

    @media (max-width: 768px) {
      .nav-menu { display: none; }
      .hamburger { display: flex; }
      .hero-content h1 { font-size: 28px; }
      section { padding: 60px 0; }
      .features-grid, .services-grid, .cases-grid, .stats-grid {
        grid-template-columns: 1fr;
      }
      .process-steps {
        flex-direction: column;
        gap: 32px;
      }
      .step-line { display: none; }
      .footer-grid {
        grid-template-columns: 1fr;
      }
    }