/* roulang page: index */
:root {
      --primary: #FF5F1F;
      --primary-dark: #E85510;
      --primary-light: #FFF0E8;
      --secondary: #1A1D23;
      --bg: #F7F8FC;
      --white: #FFFFFF;
      --text: #1F2329;
      --text-secondary: #86909C;
      --border: #E5E6EB;
      --success: #00B578;
      --warning: #FFB800;
      --error: #FA5151;
      --radius-card: 16px;
      --radius-btn: 50px;
      --radius-input: 12px;
      --shadow-sm: 0 4px 20px rgba(0,0,0,0.04), 0 1px 3px rgba(0,0,0,0.02);
      --shadow-hover: 0 12px 28px rgba(0,0,0,0.08), 0 4px 12px rgba(0,0,0,0.04);
      --transition: 250ms ease-out;
      --container-padding: 40px;
      --section-gap: 100px;
    }

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

    body {
      font-family: -apple-system, "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      background: var(--bg);
      color: var(--text);
      line-height: 1.6;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }

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

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

    button, input {
      font-family: inherit;
    }

    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding-left: var(--container-padding);
      padding-right: var(--container-padding);
    }

    /* 导航 */
    .header {
      position: sticky;
      top: 0;
      z-index: 100;
      background: rgba(255,255,255,0.85);
      backdrop-filter: blur(12px);
      border-bottom: 1px solid rgba(0,0,0,0.04);
      transition: background 0.3s;
    }

    .nav {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 72px;
    }

    .logo {
      font-size: 24px;
      font-weight: 700;
      color: var(--secondary);
      display: flex;
      align-items: center;
      gap: 8px;
    }

    .logo span {
      color: var(--primary);
    }

    .nav-links {
      display: flex;
      align-items: center;
      gap: 8px;
    }

    .nav-link {
      padding: 8px 18px;
      border-radius: 30px;
      font-size: 15px;
      font-weight: 500;
      color: var(--text-secondary);
      transition: background var(--transition), color var(--transition);
    }

    .nav-link.active {
      background: var(--primary-light);
      color: var(--primary);
    }

    .nav-link:hover {
      background: rgba(0,0,0,0.03);
      color: var(--text);
    }

    .mobile-toggle {
      display: none;
      background: none;
      border: none;
      font-size: 26px;
      color: var(--secondary);
      cursor: pointer;
    }

    /* 移动端底部导航 */
    .bottom-nav {
      display: none;
      position: fixed;
      bottom: 0;
      left: 0;
      width: 100%;
      background: var(--white);
      border-top: 1px solid var(--border);
      z-index: 99;
      justify-content: space-around;
      padding: 8px 10px;
      box-shadow: 0 -4px 10px rgba(0,0,0,0.02);
    }

    .bottom-nav-item {
      display: flex;
      flex-direction: column;
      align-items: center;
      font-size: 12px;
      color: var(--text-secondary);
      gap: 4px;
      transition: color 0.2s;
    }

    .bottom-nav-item i {
      font-size: 20px;
    }

    .bottom-nav-item.active {
      color: var(--primary);
    }

    .menu-overlay {
      position: fixed;
      inset: 0;
      background: var(--white);
      z-index: 98;
      display: flex;
      flex-direction: column;
      padding: 80px 32px;
      transform: translateX(100%);
      transition: transform 0.3s ease;
    }

    .menu-overlay.open {
      transform: translateX(0);
    }

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

    .section-title {
      font-size: 32px;
      font-weight: 600;
      margin-bottom: 16px;
      color: var(--secondary);
      position: relative;
      padding-left: 20px;
    }

    .section-title::before {
      content: '';
      position: absolute;
      left: 0;
      top: 50%;
      transform: translateY(-50%);
      width: 4px;
      height: 28px;
      background: var(--primary);
      border-radius: 4px;
    }

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

    /* Hero */
    .hero {
      background: linear-gradient(135deg, #1A1D23 0%, #3A2C2A 60%, #FF5F1F 100%);
      position: relative;
      overflow: hidden;
      color: white;
      padding: 120px 0;
    }

    .hero::before {
      content: '';
      position: absolute;
      inset: 0;
      background: url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      opacity: 0.25;
      mix-blend-mode: overlay;
    }

    .hero-content {
      position: relative;
      z-index: 2;
      display: flex;
      align-items: center;
      gap: 60px;
    }

    .hero-text {
      flex: 1;
    }

    .hero h1 {
      font-size: 48px;
      font-weight: 700;
      line-height: 1.2;
      margin-bottom: 20px;
    }

    .hero p {
      font-size: 18px;
      opacity: 0.9;
      margin-bottom: 32px;
    }

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

    .btn-primary {
      background: var(--primary);
      color: white;
      border: none;
      padding: 14px 36px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      transition: background var(--transition), transform 0.2s;
      cursor: pointer;
    }

    .btn-primary:hover {
      background: var(--primary-dark);
      transform: scale(1.02);
    }

    .btn-outline {
      background: transparent;
      border: 1.5px solid var(--primary);
      color: white;
      padding: 14px 36px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      transition: background var(--transition);
    }

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

    /* 卡片网格 */
    .grid-3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }

    .card {
      background: var(--white);
      border-radius: var(--radius-card);
      padding: 32px;
      box-shadow: var(--shadow-sm);
      transition: transform var(--transition), box-shadow var(--transition);
    }

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

    .card-icon {
      font-size: 32px;
      color: var(--primary);
      margin-bottom: 16px;
    }

    .card h3 {
      font-size: 20px;
      font-weight: 600;
      margin-bottom: 12px;
    }

    /* 服务体系2x3网格 */
    .service-grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 24px;
    }

    .service-card {
      background: var(--white);
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
      transition: all var(--transition);
      display: flex;
      flex-direction: column;
    }

    .service-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-hover);
    }

    .service-img {
      height: 180px;
      background-size: cover;
      background-position: center;
    }

    .service-body {
      padding: 24px;
    }

    /* 数据实力 */
    .stats-bg {
      background: var(--secondary);
      color: white;
      position: relative;
    }

    .stats-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      text-align: center;
      gap: 32px;
    }

    .stat-number {
      font-size: 40px;
      font-weight: 700;
      color: var(--primary);
    }

    /* 解决方案交替 */
    .solution-row {
      display: flex;
      align-items: center;
      gap: 60px;
      margin-bottom: 80px;
    }

    .solution-row.reverse {
      flex-direction: row-reverse;
    }

    .solution-img {
      flex: 1;
      border-radius: var(--radius-card);
      overflow: hidden;
      height: 320px;
      background-size: cover;
    }

    .solution-text {
      flex: 1;
    }

    /* FAQ */
    .faq-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 24px;
    }

    .faq-item {
      background: var(--white);
      border-radius: var(--radius-card);
      padding: 20px 24px;
      box-shadow: var(--shadow-sm);
      cursor: pointer;
    }

    .faq-question {
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-weight: 600;
    }

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      color: var(--text-secondary);
      margin-top: 0;
    }

    .faq-item.open .faq-answer {
      max-height: 200px;
      margin-top: 12px;
    }

    /* CTA横幅 */
    .cta-banner {
      background: linear-gradient(135deg, #4E6EF2, #2B4ACB);
      border-radius: 24px;
      padding: 60px 40px;
      text-align: center;
      color: white;
    }

    /* 页脚 */
    .footer {
      background: var(--secondary);
      color: #ccc;
      padding: 60px 0 30px;
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
    }

    @media (max-width: 1024px) {
      .container {
        padding-left: 24px;
        padding-right: 24px;
      }
      .grid-3, .stats-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .service-grid {
        grid-template-columns: 1fr;
      }
    }

    @media (max-width: 768px) {
      .nav-links { display: none; }
      .mobile-toggle { display: block; }
      .bottom-nav { display: flex; }
      .header { position: relative; }
      section { padding: 50px 0; }
      .hero { padding: 80px 0; }
      .hero h1 { font-size: 32px; }
      .grid-3, .stats-grid, .faq-grid { grid-template-columns: 1fr; }
      .solution-row, .solution-row.reverse { flex-direction: column; }
      .footer-grid { grid-template-columns: 1fr 1fr; }
    }