/* roulang page: index */
:root {
      --primary: #0A2647;
      --primary-light: #144272;
      --accent: #F4841A;
      --bg: #F8FAFC;
      --white: #FFFFFF;
      --text: #1E293B;
      --text-muted: #64748B;
      --border-light: #E2E8F0;
      --shadow-sm: 0 2px 8px rgba(10, 38, 71, 0.06);
      --shadow-md: 0 8px 24px rgba(10, 38, 71, 0.12);
      --shadow-xl: 0 16px 32px rgba(10, 38, 71, 0.18);
      --radius-sm: 8px;
      --radius-md: 12px;
      --radius-lg: 16px;
      --transition: 0.25s ease;
    }

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

    body {
      font-family: 'PingFang SC', 'Microsoft YaHei', 'Inter', 'Helvetica Neue', sans-serif;
      background-color: var(--bg);
      color: var(--text);
      line-height: 1.7;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }

    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
    }

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

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

    button, .btn {
      cursor: pointer;
      font-family: inherit;
    }

    /* 导航 */
    #main-nav {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 72px;
      background: var(--white);
      box-shadow: 0 1px 4px rgba(0,0,0,0.04);
      display: flex;
      align-items: center;
      z-index: 1000;
      transition: var(--transition);
    }

    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
    }

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

    .logo svg {
      width: 28px;
      height: 28px;
    }

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

    .nav-links a {
      font-size: 15px;
      font-weight: 500;
      color: var(--text-muted);
      padding: 6px 0;
      position: relative;
      transition: color var(--transition);
    }

    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: -4px;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--primary);
      transition: width var(--transition);
    }

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

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

    .nav-cta {
      background: var(--accent);
      color: var(--white);
      padding: 8px 20px;
      border-radius: var(--radius-sm);
      font-weight: 600;
      font-size: 14px;
      transition: background var(--transition), transform var(--transition);
    }

    .nav-cta:hover {
      background: #e07b0e;
      transform: translateY(-1px);
    }

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

    .hamburger span {
      width: 24px;
      height: 2px;
      background: var(--primary);
      transition: var(--transition);
      border-radius: 2px;
    }

    /* 区块间距 */
    section {
      padding: 100px 0;
    }

    @media (max-width: 768px) {
      section {
        padding: 60px 0;
      }
    }

    /* Hero */
    #hero {
      padding-top: 140px;
      padding-bottom: 80px;
    }

    .hero-grid {
      display: flex;
      align-items: center;
      gap: 60px;
    }

    .hero-text {
      flex: 1 1 55%;
    }

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

    .hero-sub {
      font-size: 18px;
      color: var(--text-muted);
      margin-bottom: 32px;
      line-height: 1.6;
    }

    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
      margin-bottom: 40px;
    }

    .btn-primary {
      background: var(--primary);
      color: white;
      padding: 14px 32px;
      border-radius: var(--radius-sm);
      font-weight: 600;
      border: none;
      transition: all var(--transition);
      display: inline-block;
      text-align: center;
    }

    .btn-primary:hover {
      background: var(--accent);
      transform: translateY(-2px);
      box-shadow: var(--shadow-md);
    }

    .btn-outline {
      background: transparent;
      color: var(--primary);
      border: 2px solid var(--primary);
      padding: 14px 32px;
      border-radius: var(--radius-sm);
      font-weight: 600;
      transition: all var(--transition);
      display: inline-block;
      text-align: center;
    }

    .btn-outline:hover {
      background: rgba(10,38,71,0.08);
      transform: translateY(-2px);
      box-shadow: var(--shadow-sm);
    }

    .badge-group {
      display: flex;
      gap: 32px;
    }

    .badge-item {
      text-align: left;
    }

    .badge-num {
      font-size: 40px;
      font-weight: 800;
      color: var(--accent);
      line-height: 1;
    }

    .badge-label {
      font-size: 13px;
      color: var(--text-muted);
      margin-top: 6px;
    }

    .hero-image {
      flex: 1 1 45%;
      border-radius: var(--radius-lg);
      overflow: hidden;
      box-shadow: var(--shadow-md);
    }

    .hero-image img {
      width: 100%;
      height: auto;
      object-fit: cover;
    }

    /* 优势网格 */
    .section-title {
      font-size: 32px;
      font-weight: 600;
      text-align: center;
      margin-bottom: 48px;
      color: var(--text);
      position: relative;
    }

    .section-title::after {
      content: '';
      position: absolute;
      bottom: -12px;
      left: 50%;
      transform: translateX(-50%);
      width: 60px;
      height: 4px;
      background: var(--accent);
      border-radius: 2px;
    }

    .advantages-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 32px;
    }

    .adv-card {
      background: var(--white);
      padding: 32px 24px;
      border-radius: var(--radius-md);
      box-shadow: var(--shadow-sm);
      text-align: center;
      transition: box-shadow var(--transition), transform var(--transition);
    }

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

    .adv-icon {
      margin-bottom: 16px;
      display: flex;
      justify-content: center;
    }

    .adv-icon svg {
      width: 48px;
      height: 48px;
      stroke: var(--primary);
    }

    .adv-title {
      font-size: 18px;
      font-weight: 600;
      margin-bottom: 8px;
    }

    .adv-desc {
      font-size: 14px;
      color: var(--text-muted);
    }

    /* 服务案例瀑布流 */
    .services-header {
      display: flex;
      justify-content: space-between;
      align-items: baseline;
      margin-bottom: 48px;
    }

    .services-header .section-title {
      margin-bottom: 0;
    }

    .view-all {
      color: var(--text-muted);
      font-size: 14px;
      font-weight: 500;
      transition: color var(--transition);
    }

    .case-row {
      display: flex;
      gap: 24px;
      margin-bottom: 24px;
      align-items: start;
    }

    .case-card {
      background: var(--white);
      border-radius: var(--radius-md);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
      transition: all var(--transition);
    }

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

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

    .case-img {
      overflow: hidden;
      aspect-ratio: 16/9;
    }

    .case-img img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      transition: transform 0.4s ease;
    }

    .case-content {
      padding: 20px;
    }

    .case-title {
      font-size: 18px;
      font-weight: 600;
      margin-bottom: 6px;
    }

    .case-summary {
      font-size: 14px;
      color: var(--text-muted);
      margin-bottom: 12px;
    }

    .tag {
      display: inline-block;
      background: rgba(244, 132, 26, 0.1);
      color: var(--accent);
      font-size: 12px;
      font-weight: 500;
      padding: 4px 12px;
      border-radius: 20px;
    }

    .large-card {
      flex: 0 0 66%;
    }

    .small-card {
      flex: 0 0 32%;
    }

    /* 数据滚动条 */
    .stats-band {
      background: rgba(10, 38, 71, 0.04);
      padding: 60px 0;
    }

    .stats-flex {
      display: flex;
      justify-content: space-around;
      text-align: center;
      flex-wrap: wrap;
    }

    .stat-item .stat-num {
      font-size: 40px;
      font-weight: 800;
      color: var(--accent);
      line-height: 1.2;
    }

    .stat-label {
      font-size: 14px;
      color: var(--text-muted);
    }

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

    .faq-item {
      background: var(--white);
      border-radius: var(--radius-md);
      box-shadow: var(--shadow-sm);
      overflow: hidden;
      border: 1px solid var(--border-light);
      transition: border var(--transition);
    }

    .faq-question {
      width: 100%;
      background: transparent;
      border: none;
      padding: 20px;
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-size: 16px;
      font-weight: 600;
      color: var(--text);
      cursor: pointer;
      text-align: left;
    }

    .faq-icon {
      font-size: 20px;
      font-weight: 400;
      transition: transform 0.2s;
      color: var(--primary);
    }

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      padding: 0 20px;
      font-size: 14px;
      color: var(--text-muted);
      transition: max-height 0.3s ease, padding 0.3s ease;
    }

    .faq-item.open {
      border-color: var(--primary);
    }

    .faq-item.open .faq-answer {
      max-height: 200px;
      padding: 0 20px 20px;
    }

    /* CTA 横幅 */
    .cta-banner {
      background: linear-gradient(135deg, #0A2647 0%, #144272 100%);
      text-align: center;
      padding: 80px 0;
    }

    .cta-title {
      font-size: 32px;
      font-weight: 700;
      color: white;
      margin-bottom: 16px;
    }

    .cta-sub {
      color: rgba(255,255,255,0.8);
      margin-bottom: 32px;
    }

    .btn-accent {
      background: var(--accent);
      color: white;
      padding: 16px 40px;
      border-radius: var(--radius-sm);
      font-weight: 700;
      font-size: 16px;
      border: none;
      transition: var(--transition);
    }

    .btn-accent:hover {
      background: #e07b0e;
      transform: translateY(-2px);
    }

    /* 页脚 */
    footer {
      background: var(--primary);
      color: rgba(255,255,255,0.85);
      padding: 60px 0 0;
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1.5fr 1.5fr;
      gap: 32px;
      margin-bottom: 40px;
    }

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

    .footer-desc {
      font-size: 14px;
      margin-bottom: 16px;
    }

    .footer-title {
      color: white;
      font-weight: 600;
      margin-bottom: 16px;
    }

    .footer-links a {
      display: block;
      color: rgba(255,255,255,0.7);
      font-size: 14px;
      margin-bottom: 8px;
      transition: color var(--transition);
    }

    .footer-links a:hover {
      color: var(--accent);
    }

    .copyright {
      border-top: 1px solid rgba(255,255,255,0.15);
      padding: 20px 0;
      text-align: center;
      font-size: 13px;
      color: rgba(255,255,255,0.6);
    }

    @media (max-width: 1024px) {
      .hero-grid {
        flex-direction: column;
      }
      .advantages-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .case-row {
        flex-direction: column;
      }
      .large-card, .small-card {
        flex: 1 1 100%;
      }
    }

    @media (max-width: 768px) {
      .nav-links {
        display: none;
        position: fixed;
        top: 72px;
        left: 0;
        background: white;
        width: 100%;
        flex-direction: column;
        padding: 32px;
        gap: 24px;
        box-shadow: var(--shadow-md);
      }
      .nav-links.show {
        display: flex;
      }
      .hamburger {
        display: flex;
      }
      .hero-title {
        font-size: 36px;
      }
      .advantages-grid {
        grid-template-columns: 1fr;
      }
      .faq-grid {
        grid-template-columns: 1fr;
      }
      .stats-flex {
        gap: 24px;
      }
      .footer-grid {
        grid-template-columns: 1fr;
      }
      .badge-group {
        flex-direction: column;
        gap: 16px;
      }
      .btn-primary, .btn-outline {
        width: 100%;
        text-align: center;
      }
    }