/* roulang page: index */
:root {
      --primary: #1A5F4A;
      --primary-dark: #154D3D;
      --primary-light: #E8F5F0;
      --accent: #F5A623;
      --accent-light: #FFF3E0;
      --success: #00B578;
      --warning: #FF9F0A;
      --error: #FA5151;
      --bg: #F5F6FA;
      --surface: #FFFFFF;
      --text-primary: #1F2329;
      --text-secondary: #86909C;
      --text-muted: #B0B8C1;
      --border: #E8ECF1;
      --radius-sm: 8px;
      --radius: 12px;
      --radius-lg: 20px;
      --shadow-sm: 0 2px 12px rgba(0, 0, 0, 0.06);
      --shadow-hover: 0 8px 24px rgba(0, 0, 0, 0.10);
      --font-system: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Inter", sans-serif;
      --transition: 200ms ease;
    }

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

    body {
      font-family: var(--font-system);
      background-color: var(--bg);
      color: var(--text-primary);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
      -moz-osx-font-smoothing: grayscale;
    }

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

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

    button, input, textarea {
      font-family: inherit;
    }

    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 24px;
    }

    /* 导航栏 */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 64px;
      background: var(--surface);
      border-bottom: 1px solid var(--border);
      z-index: 1000;
      display: flex;
      align-items: center;
      backdrop-filter: blur(8px);
      background: rgba(255,255,255,0.92);
    }

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

    .logo {
      display: flex;
      align-items: center;
      gap: 8px;
      font-weight: 700;
      font-size: 22px;
      color: var(--primary);
      letter-spacing: -0.3px;
    }
    .logo-icon {
      width: 32px;
      height: 32px;
      background: var(--primary);
      border-radius: 8px;
      display: flex;
      align-items: center;
      justify-content: center;
      color: white;
      font-weight: bold;
      font-size: 18px;
    }

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

    .nav-link {
      font-size: 16px;
      font-weight: 500;
      color: var(--text-primary);
      position: relative;
      padding: 8px 0;
      transition: color var(--transition);
    }
    .nav-link:hover {
      color: var(--primary);
    }
    .nav-link::after {
      content: '';
      position: absolute;
      bottom: -2px;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--primary);
      transition: width var(--transition);
    }
    .nav-link:hover::after {
      width: 100%;
    }

    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
      background: transparent;
      border: none;
      padding: 8px;
      z-index: 1001;
    }
    .hamburger span {
      display: block;
      width: 24px;
      height: 2px;
      background: var(--text-primary);
      border-radius: 2px;
      transition: all 0.3s ease;
    }

    /* 移动端菜单 */
    .mobile-menu {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100vh;
      background: white;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      gap: 24px;
      transform: translateY(-100%);
      transition: transform 0.3s ease;
      z-index: 999;
      list-style: none;
    }
    .mobile-menu.active {
      transform: translateY(0);
    }
    .mobile-menu .nav-link {
      font-size: 20px;
      font-weight: 600;
    }

    /* 区块间距 */
    section {
      padding: 80px 0;
    }

    /* 首屏 Hero */
    .hero {
      background: var(--surface);
      padding-top: 120px;
      padding-bottom: 80px;
    }
    .hero-grid {
      display: flex;
      align-items: center;
      gap: 48px;
    }
    .hero-left {
      flex: 5;
    }
    .hero-right {
      flex: 7;
    }
    .hero-title {
      font-size: 36px;
      font-weight: 700;
      line-height: 1.3;
      color: var(--text-primary);
      margin-bottom: 16px;
    }
    .hero-sub {
      font-size: 18px;
      color: var(--text-secondary);
      margin-bottom: 32px;
    }
    .btn-group {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 12px 28px;
      border-radius: var(--radius-sm);
      font-weight: 600;
      font-size: 16px;
      transition: all var(--transition);
      cursor: pointer;
      border: 2px solid transparent;
    }
    .btn-primary {
      background: var(--primary);
      color: white;
    }
    .btn-primary:hover {
      background: var(--primary-dark);
    }
    .btn-outline {
      background: transparent;
      border-color: var(--primary);
      color: var(--primary);
    }
    .btn-outline:hover {
      background: var(--primary-light);
    }
    .hero-image {
      width: 100%;
      border-radius: var(--radius);
      box-shadow: var(--shadow-sm);
      object-fit: cover;
      aspect-ratio: 4/3;
    }

    /* 区块标题 */
    .section-title {
      font-size: 28px;
      font-weight: 700;
      margin-bottom: 16px;
      color: var(--text-primary);
    }
    .section-sub {
      font-size: 16px;
      color: var(--text-secondary);
      max-width: 640px;
      margin-bottom: 48px;
    }

    /* 核心优势 */
    .features-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 32px;
    }
    .feature-card {
      background: var(--surface);
      padding: 32px 24px;
      border-radius: var(--radius);
      text-align: center;
      transition: box-shadow var(--transition);
    }
    .feature-icon {
      width: 64px;
      height: 64px;
      background: var(--primary-light);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      margin: 0 auto 20px;
      color: var(--primary);
      font-size: 28px;
    }
    .feature-title {
      font-size: 20px;
      font-weight: 600;
      margin-bottom: 12px;
    }

    /* 服务项目 */
    .service-row {
      display: flex;
      align-items: center;
      gap: 48px;
      margin-bottom: 64px;
    }
    .service-row.reverse {
      flex-direction: row-reverse;
    }
    .service-img {
      flex: 1;
      border-radius: var(--radius);
      overflow: hidden;
    }
    .service-img img {
      width: 100%;
      border-radius: var(--radius);
      transition: transform 0.3s ease;
    }
    .service-img:hover img {
      transform: scale(1.02);
    }
    .service-content {
      flex: 1;
    }
    .service-list {
      list-style: none;
      margin: 16px 0;
    }
    .service-list li {
      display: flex;
      align-items: center;
      gap: 8px;
      font-size: 14px;
      color: var(--primary);
      margin-bottom: 8px;
    }
    .text-link {
      color: var(--primary);
      font-weight: 600;
      display: inline-flex;
      align-items: center;
      gap: 4px;
      transition: gap 0.2s;
    }
    .text-link:hover {
      gap: 8px;
    }

    /* 案例瀑布流 */
    .case-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .case-card {
      position: relative;
      border-radius: var(--radius);
      overflow: hidden;
      aspect-ratio: 4/3;
      cursor: pointer;
    }
    .case-card img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      transition: transform 0.3s ease;
    }
    .case-overlay {
      position: absolute;
      bottom: 0;
      left: 0;
      width: 100%;
      padding: 24px 16px;
      background: linear-gradient(transparent, rgba(0,0,0,0.7));
      color: white;
      font-weight: 600;
      font-size: 18px;
    }
    .case-card:hover img {
      transform: scale(1.05);
    }

    /* 关于我们 */
    .about-grid {
      display: flex;
      align-items: center;
      gap: 48px;
    }
    .about-text {
      flex: 1;
    }
    .stats {
      display: flex;
      gap: 32px;
      margin-top: 24px;
    }
    .stat-number {
      font-size: 32px;
      font-weight: 700;
      color: var(--accent);
    }
    .about-image {
      flex: 1;
      border-radius: var(--radius);
      overflow: hidden;
    }

    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }
    .faq-item {
      background: var(--surface);
      border-radius: var(--radius);
      padding: 20px;
      margin-bottom: 12px;
      cursor: pointer;
    }
    .faq-question {
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-weight: 600;
    }
    .faq-icon {
      font-size: 20px;
      color: var(--primary);
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      color: var(--text-secondary);
      font-size: 14px;
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      margin-top: 12px;
    }

    /* CTA */
    .cta-section {
      background: linear-gradient(135deg, #E8F5F0 0%, #CDECDA 100%);
    }
    .cta-form {
      display: flex;
      flex-direction: column;
      gap: 16px;
      max-width: 480px;
      margin: 32px auto 0;
    }
    .input-field {
      padding: 14px 18px;
      border-radius: var(--radius-sm);
      border: 1px solid var(--border);
      background: var(--surface);
      font-size: 16px;
      transition: 0.2s;
    }
    .input-field:focus {
      outline: none;
      border-color: var(--primary);
      box-shadow: 0 0 0 3px rgba(26,95,74,0.1);
    }

    /* 页脚 */
    .footer {
      background: #1F2329;
      color: #B0B8C1;
      padding: 48px 0 24px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1.5fr;
      gap: 32px;
    }
    .footer-title {
      color: white;
      font-weight: 600;
      margin-bottom: 16px;
    }
    .copyright {
      border-top: 1px solid #2E3338;
      margin-top: 32px;
      padding-top: 24px;
      text-align: center;
      font-size: 14px;
    }

    /* 响应式 */
    @media (max-width: 1024px) {
      .hero-grid, .service-row, .about-grid {
        flex-direction: column;
      }
      .case-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .footer-grid {
        grid-template-columns: repeat(2, 1fr);
      }
    }
    @media (max-width: 768px) {
      .nav-menu {
        display: none;
      }
      .hamburger {
        display: flex;
      }
      .features-grid {
        grid-template-columns: 1fr;
      }
      .case-grid {
        grid-template-columns: 1fr;
      }
      .hero-title {
        font-size: 28px;
      }
      .section-title {
        font-size: 22px;
      }
      .stats {
        flex-wrap: wrap;
      }
      .footer-grid {
        grid-template-columns: 1fr;
      }
    }