/* roulang page: index */
:root {
      --primary: #F15A24;
      --primary-dark: #E04A1A;
      --secondary: #1E1E1E;
      --gray-bg: #F2F2F2;
      --accent: #00E5A1;
      --text-main: #1E1E1E;
      --text-body: #333333;
      --text-muted: #666666;
      --white: #FFFFFF;
      --border-light: #DDDDDD;
      --shadow-sm: 0 4px 20px rgba(0,0,0,0.04);
      --shadow-md: 0 12px 32px rgba(0,0,0,0.08);
      --radius-sm: 8px;
      --radius-md: 16px;
      --transition: all 0.3s ease;
      --font-sans: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", sans-serif;
      --font-number: "Inter", "SF Pro Display", system-ui, sans-serif;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    html {
      scroll-behavior: smooth;
    }
    body {
      font-family: var(--font-sans);
      color: var(--text-body);
      background-color: var(--white);
      line-height: 1.5;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }
    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 24px;
    }
    h1, h2, h3 {
      font-weight: 700;
      color: var(--text-main);
    }
    h1 {
      font-size: 48px;
      line-height: 1.2;
      letter-spacing: -0.5px;
      font-weight: 800;
    }
    h2 {
      font-size: 36px;
      line-height: 1.3;
      margin-bottom: 16px;
    }
    h3 {
      font-size: 22px;
      font-weight: 600;
      line-height: 1.4;
    }
    p {
      color: var(--text-muted);
      line-height: 1.6;
    }
    a {
      text-decoration: none;
      color: inherit;
      transition: var(--transition);
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    button, .btn {
      font-family: inherit;
      cursor: pointer;
      border: none;
      background: none;
      font-weight: 600;
      transition: var(--transition);
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
    }
    .btn-primary {
      background: var(--primary);
      color: var(--white);
      padding: 14px 32px;
      border-radius: var(--radius-sm);
      font-weight: 600;
      box-shadow: 0 4px 12px rgba(241,90,36,0.25);
    }
    .btn-primary:hover {
      background: var(--primary-dark);
      box-shadow: 0 0 16px rgba(0,229,161,0.4);
      transform: translateY(-2px);
    }
    .btn-outline {
      background: transparent;
      border: 2px solid var(--primary);
      color: var(--primary);
      padding: 12px 30px;
      border-radius: var(--radius-sm);
      font-weight: 600;
    }
    .btn-outline:hover {
      background: var(--primary);
      color: var(--white);
    }
    /* 导航栏 */
    .site-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      background: rgba(255,255,255,0.92);
      backdrop-filter: blur(12px);
      box-shadow: 0 1px 0 rgba(0,0,0,0.05);
      z-index: 100;
      height: 72px;
      display: flex;
      align-items: center;
    }
    .header-inner {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
    }
    .logo {
      display: flex;
      align-items: center;
      gap: 8px;
      font-weight: 800;
      font-size: 22px;
      color: var(--text-main);
      letter-spacing: 1px;
    }
    .logo-icon {
      width: 32px;
      height: 32px;
      background: var(--primary);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      color: white;
      font-size: 18px;
    }
    .nav-menu {
      display: flex;
      align-items: center;
      gap: 32px;
      list-style: none;
    }
    .nav-menu a {
      font-weight: 500;
      color: var(--text-main);
      position: relative;
      padding: 8px 0;
    }
    .nav-menu a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--primary);
      transition: width 0.3s ease;
    }
    .nav-menu a:hover::after,
    .nav-menu a.active::after {
      width: 100%;
    }
    .nav-actions {
      display: flex;
      align-items: center;
      gap: 16px;
    }
    .search-icon {
      font-size: 20px;
      color: var(--text-muted);
      cursor: pointer;
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
    }
    .hamburger span {
      width: 24px;
      height: 2px;
      background: var(--text-main);
      transition: var(--transition);
    }
    /* Hero */
    .hero {
      padding: 140px 0 80px;
      background: var(--gray-bg);
    }
    .hero-grid {
      display: flex;
      align-items: center;
      gap: 60px;
    }
    .hero-content {
      flex: 1;
    }
    .hero-badge {
      display: inline-block;
      background: rgba(0,229,161,0.15);
      color: var(--accent);
      font-weight: 600;
      font-size: 13px;
      padding: 6px 14px;
      border-radius: 30px;
      margin-bottom: 20px;
    }
    .hero-title {
      margin-bottom: 20px;
    }
    .hero-sub {
      font-size: 18px;
      color: var(--text-muted);
      margin-bottom: 32px;
      max-width: 480px;
    }
    .hero-stats {
      display: flex;
      gap: 30px;
      margin-bottom: 36px;
    }
    .stat-item {
      background: white;
      padding: 12px 18px;
      border-radius: var(--radius-sm);
      box-shadow: var(--shadow-sm);
    }
    .stat-number {
      font-family: var(--font-number);
      font-weight: 800;
      font-size: 28px;
      color: var(--accent);
      display: block;
    }
    .hero-image {
      flex: 1;
      border-radius: var(--radius-md);
      overflow: hidden;
      box-shadow: var(--shadow-md);
    }
    .hero-image img {
      width: 100%;
      height: auto;
      object-fit: cover;
    }
    /* 板块通用 */
    .section {
      padding: 100px 0;
    }
    .section-header {
      text-align: center;
      max-width: 700px;
      margin: 0 auto 60px;
    }
    .section-gray {
      background: var(--gray-bg);
    }
    /* 服务卡片 */
    .services-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 30px;
    }
    .service-card {
      background: var(--white);
      padding: 32px;
      border-radius: var(--radius-md);
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
    }
    .service-card:hover {
      transform: translateY(-8px);
      box-shadow: var(--shadow-md);
    }
    .service-icon {
      width: 50px;
      height: 50px;
      background: rgba(241,90,36,0.1);
      border-radius: 12px;
      display: flex;
      align-items: center;
      justify-content: center;
      color: var(--primary);
      font-size: 24px;
      margin-bottom: 20px;
    }
    .service-card h3 {
      margin-bottom: 12px;
    }
    .service-link {
      color: var(--primary);
      font-weight: 600;
      margin-top: 16px;
      display: inline-flex;
      align-items: center;
      gap: 6px;
    }
    /* 数据区 */
    .data-section {
      background: var(--secondary);
      color: white;
      padding: 80px 0;
    }
    .data-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 40px;
      text-align: center;
    }
    .data-item .number {
      font-family: var(--font-number);
      font-size: 56px;
      font-weight: 800;
      color: var(--accent);
      display: block;
    }
    .data-item .label {
      color: rgba(255,255,255,0.8);
      margin-top: 8px;
    }
    /* 案例 */
    .cases-grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 30px;
    }
    .case-card {
      background: white;
      border-radius: var(--radius-md);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
    }
    .case-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-md);
    }
    .case-img {
      height: 260px;
      background-size: cover;
      background-position: center;
    }
    .case-body {
      padding: 24px;
    }
    .case-tag {
      background: rgba(0,229,161,0.2);
      color: #0a7e5e;
      font-weight: 600;
      font-size: 12px;
      padding: 4px 12px;
      border-radius: 20px;
      display: inline-block;
      margin-bottom: 12px;
    }
    /* 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-md);
      overflow: hidden;
    }
    .solution-text {
      flex: 1;
    }
    .solution-list {
      list-style: none;
      margin-top: 20px;
    }
    .solution-list li {
      display: flex;
      align-items: flex-start;
      gap: 12px;
      margin-bottom: 12px;
    }
    .solution-list li::before {
      content: '●';
      color: var(--primary);
      font-size: 18px;
    }
    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }
    .faq-item {
      background: var(--gray-bg);
      border-radius: var(--radius-md);
      margin-bottom: 12px;
      overflow: hidden;
      transition: var(--transition);
    }
    .faq-question {
      padding: 20px 24px;
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      cursor: pointer;
      background: var(--gray-bg);
    }
    .faq-answer {
      padding: 0 24px 20px;
      color: var(--text-muted);
      display: none;
    }
    .faq-item.active {
      background: white;
      box-shadow: var(--shadow-sm);
    }
    .faq-item.active .faq-answer {
      display: block;
    }
    /* CTA */
    .cta-banner {
      background: linear-gradient(135deg, #F15A24 0%, #FF7A45 100%);
      padding: 80px 0;
      text-align: center;
      color: white;
    }
    .cta-form {
      display: flex;
      gap: 16px;
      max-width: 700px;
      margin: 30px auto 0;
      flex-wrap: wrap;
      justify-content: center;
    }
    .cta-input {
      flex: 1 1 200px;
      padding: 14px 16px;
      border-radius: var(--radius-sm);
      border: none;
      background: white;
      font-size: 16px;
    }
    .btn-white {
      background: white;
      color: var(--primary);
      font-weight: 700;
      padding: 14px 32px;
      border-radius: var(--radius-sm);
    }
    /* Footer */
    .footer {
      background: var(--secondary);
      color: #ccc;
      padding: 60px 0 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 30px;
    }
    .back-to-top {
      position: fixed;
      bottom: 24px;
      right: 24px;
      background: var(--primary);
      color: white;
      width: 44px;
      height: 44px;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      box-shadow: var(--shadow-md);
    }
    @media (max-width: 1024px) {
      .services-grid { grid-template-columns: repeat(2,1fr); }
      .data-grid { grid-template-columns: repeat(2,1fr); }
    }
    @media (max-width: 768px) {
      .nav-menu, .nav-actions .btn-primary { display: none; }
      .hamburger { display: flex; }
      .hero-grid { flex-direction: column; }
      h1 { font-size: 32px; }
      h2 { font-size: 28px; }
      .services-grid, .cases-grid { grid-template-columns: 1fr; }
      .data-grid { grid-template-columns: 1fr 1fr; }
      .solution-row, .solution-row.reverse { flex-direction: column; }
      .footer-grid { grid-template-columns: 1fr 1fr; }
    }