/* roulang page: index */
:root {
      --primary: #1A5F4A;
      --primary-deep: #154F3E;
      --primary-light: #E8F2EF;
      --accent: #F5A623;
      --accent-light: #FFF3E0;
      --bg: #F7F8FA;
      --white: #FFFFFF;
      --text: #1A1D23;
      --gray: #7B8290;
      --border: #EBEDF0;
      --success: #00A86B;
      --warning: #F59E0B;
      --error: #E84040;
      --radius-lg: 16px;
      --radius-md: 12px;
      --radius-sm: 8px;
      --shadow-card: 0 2px 12px rgba(0,0,0,0.04);
      --shadow-hover: 0 8px 24px rgba(0,0,0,0.08);
      --font-sans: system-ui, -apple-system, "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      --max-width: 1200px;
      --header-height: 72px;
    }
    
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    
    body {
      font-family: var(--font-sans);
      background: var(--bg);
      color: var(--text);
      line-height: 1.5;
      -webkit-font-smoothing: antialiased;
      -moz-osx-font-smoothing: grayscale;
    }
    
    .container {
      width: 100%;
      max-width: var(--max-width);
      margin: 0 auto;
      padding-left: 32px;
      padding-right: 32px;
    }
    
    img {
      max-width: 100%;
      display: block;
      height: auto;
    }
    
    a {
      text-decoration: none;
      color: inherit;
      transition: color 0.2s ease;
    }
    
    button, .btn {
      cursor: pointer;
      font-family: inherit;
      border: none;
      outline: none;
      transition: all 0.25s ease;
    }
    
    h1, h2, h3, h4 {
      font-weight: 600;
    }
    
    h1 {
      font-size: 36px;
      line-height: 1.25;
      font-weight: 700;
      color: var(--text);
    }
    
    h2 {
      font-size: 28px;
      line-height: 1.35;
      letter-spacing: -0.01em;
    }
    
    h3 {
      font-size: 20px;
      line-height: 1.4;
    }
    
    .text-body {
      font-size: 16px;
      line-height: 1.6;
      color: var(--gray);
    }
    
    .text-small {
      font-size: 14px;
      line-height: 1.5;
      color: var(--gray);
    }
    
    /* 导航 */
    .header {
      position: sticky;
      top: 0;
      z-index: 100;
      background: var(--white);
      height: var(--header-height);
      display: flex;
      align-items: center;
      border-bottom: 1px solid transparent;
      transition: box-shadow 0.3s ease;
    }
    
    .header.scrolled {
      box-shadow: 0 1px 8px rgba(0,0,0,0.06);
      border-bottom-color: var(--border);
    }
    
    .nav {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
    }
    
    .logo {
      font-size: 22px;
      font-weight: 700;
      color: var(--primary);
      letter-spacing: 0.5px;
      display: flex;
      align-items: center;
      gap: 6px;
    }
    
    .logo span {
      color: var(--text);
      font-weight: 400;
      font-size: 14px;
      margin-left: 4px;
      color: var(--gray);
    }
    
    .nav-links {
      display: flex;
      align-items: center;
      gap: 32px;
    }
    
    .nav-links a {
      font-size: 15px;
      font-weight: 500;
      color: var(--text);
      padding: 8px 0;
      position: relative;
    }
    
    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--primary);
      transition: width 0.2s ease;
    }
    
    .nav-links a:hover {
      color: var(--primary);
    }
    
    .nav-links a:hover::after,
    .nav-links a.active::after {
      width: 100%;
    }
    
    .btn-primary {
      background: var(--primary);
      color: white;
      border-radius: 40px;
      padding: 12px 28px;
      font-weight: 600;
      font-size: 15px;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      box-shadow: 0 4px 10px rgba(26,95,74,0.15);
    }
    
    .btn-primary:hover {
      background: var(--primary-deep);
      transform: translateY(-2px);
      box-shadow: 0 8px 16px rgba(26,95,74,0.2);
    }
    
    .btn-outline {
      background: transparent;
      border: 1.5px solid var(--primary);
      color: var(--primary);
      border-radius: 40px;
      padding: 12px 28px;
      font-weight: 600;
      font-size: 15px;
    }
    
    .btn-outline:hover {
      background: var(--primary-light);
      border-color: var(--primary-deep);
      color: var(--primary-deep);
    }
    
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
      background: none;
      border: none;
    }
    
    .hamburger span {
      width: 24px;
      height: 2px;
      background: var(--text);
      transition: all 0.3s;
    }
    
    /* Hero */
    .hero {
      background: var(--white);
      padding: 60px 0 80px;
    }
    
    .hero-grid {
      display: flex;
      align-items: center;
      gap: 60px;
    }
    
    .hero-content {
      flex: 0 0 55%;
    }
    
    .hero-content h1 {
      margin-bottom: 20px;
      color: var(--text);
    }
    
    .hero-content .subtitle {
      font-size: 16px;
      color: var(--gray);
      margin-bottom: 32px;
      max-width: 480px;
    }
    
    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    
    .hero-image {
      flex: 1;
      background: #F0F4F2;
      border-radius: var(--radius-lg);
      overflow: hidden;
      display: flex;
      align-items: center;
      justify-content: center;
    }
    
    .hero-image img {
      width: 100%;
      height: auto;
      object-fit: cover;
    }
    
    /* 板块通用 */
    .section {
      padding: 80px 0;
    }
    
    .section-header {
      text-align: center;
      margin-bottom: 48px;
    }
    
    .section-header h2 {
      margin-bottom: 12px;
    }
    
    .section-header p {
      color: var(--gray);
      max-width: 600px;
      margin: 0 auto;
    }
    
    /* 优势卡片 */
    .card-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    
    .advantage-card {
      background: var(--white);
      border-radius: var(--radius-md);
      padding: 32px 24px;
      box-shadow: var(--shadow-card);
      border: 1px solid var(--border);
      transition: all 0.3s ease;
      text-align: left;
    }
    
    .advantage-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
    }
    
    .icon-box {
      width: 48px;
      height: 48px;
      background: var(--primary-light);
      border-radius: var(--radius-sm);
      display: flex;
      align-items: center;
      justify-content: center;
      margin-bottom: 20px;
      color: var(--primary);
      font-size: 24px;
    }
    
    .advantage-card h3 {
      margin-bottom: 10px;
    }
    
    /* 服务卡片 */
    .service-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    
    .service-card {
      background: var(--white);
      border-radius: var(--radius-lg);
      overflow: hidden;
      box-shadow: var(--shadow-card);
      border: 1px solid var(--border);
      transition: all 0.3s;
    }
    
    .service-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
    }
    
    .service-img {
      height: 180px;
      background: #eef2f0;
    }
    
    .service-img img {
      width: 100%;
      height: 100%;
      object-fit: cover;
    }
    
    .service-body {
      padding: 24px;
    }
    
    .service-body h3 {
      margin-bottom: 8px;
    }
    
    .link-arrow {
      color: var(--primary);
      font-weight: 600;
      margin-top: 12px;
      display: inline-block;
    }
    
    /* 数据区 */
    .data-section {
      background: var(--white);
    }
    
    .data-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 20px;
    }
    
    .data-item {
      background: var(--bg);
      border-radius: var(--radius-md);
      padding: 32px 16px;
      text-align: center;
      border: 1px solid var(--border);
    }
    
    .data-number {
      font-size: 48px;
      font-weight: 700;
      color: var(--accent);
      line-height: 1.1;
    }
    
    /* 解决方案交错 */
    .solution-row {
      display: flex;
      align-items: center;
      gap: 60px;
      margin-bottom: 80px;
    }
    
    .solution-row.reverse {
      flex-direction: row-reverse;
    }
    
    .solution-text {
      flex: 1;
    }
    
    .solution-text h2 {
      margin-bottom: 16px;
    }
    
    .solution-img {
      flex: 1;
      background: #eef2f0;
      border-radius: var(--radius-lg);
      overflow: hidden;
    }
    
    /* 案例卡片 */
    .case-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    
    .case-card {
      border-radius: var(--radius-lg);
      overflow: hidden;
      position: relative;
      background: #ddd;
    }
    
    .case-card img {
      width: 100%;
      aspect-ratio: 16/10;
      object-fit: cover;
      transition: transform 0.4s;
    }
    
    .case-card:hover img {
      transform: scale(1.03);
    }
    
    .case-info {
      position: absolute;
      bottom: 0;
      left: 0;
      right: 0;
      padding: 24px;
      background: linear-gradient(transparent, rgba(0,0,0,0.7));
      color: white;
    }
    
    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }
    
    .faq-item {
      border-bottom: 1px solid var(--border);
      padding: 20px 0;
    }
    
    .faq-question {
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-weight: 600;
      font-size: 18px;
      cursor: pointer;
    }
    
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      color: var(--gray);
      font-size: 16px;
    }
    
    .faq-item.active .faq-answer {
      max-height: 200px;
      padding-top: 12px;
    }
    
    /* CTA */
    .cta-block {
      background: var(--primary);
      color: white;
      text-align: center;
      padding: 80px 0;
    }
    
    .cta-block h2 {
      color: white;
      margin-bottom: 16px;
    }
    
    .btn-light {
      background: white;
      color: var(--primary);
      border-radius: 40px;
      padding: 14px 36px;
      font-weight: 700;
      margin-top: 24px;
    }
    
    /* Footer */
    .footer {
      background: #1A1D23;
      color: #ccc;
      padding: 60px 0 30px;
    }
    
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
    }
    
    .footer a {
      color: #aaa;
      display: block;
      margin-bottom: 6px;
    }
    
    .copyright {
      border-top: 1px solid #2a2f36;
      margin-top: 40px;
      padding-top: 20px;
      text-align: center;
      color: #777;
      font-size: 14px;
    }
    
    @media (max-width: 1024px) {
      .container { padding-left: 24px; padding-right: 24px; }
      .card-grid, .service-grid, .case-grid { grid-template-columns: repeat(2, 1fr); }
      .data-grid { grid-template-columns: repeat(2, 1fr); }
    }
    
    @media (max-width: 768px) {
      h1 { font-size: 28px; }
      .nav-links { display: none; }
      .hamburger { display: flex; }
      .hero-grid { flex-direction: column; }
      .hero-content { flex: auto; }
      .card-grid, .service-grid, .case-grid, .data-grid { grid-template-columns: 1fr; }
      .solution-row, .solution-row.reverse { flex-direction: column; }
      .footer-grid { grid-template-columns: 1fr 1fr; }
    }