/* roulang page: index */
:root {
      --primary: #0A66C2;
      --primary-deep: #084E9E;
      --accent: #F5A623;
      --accent-deep: #E0950F;
      --bg-white: #FFFFFF;
      --bg-light: #F7F9FC;
      --bg-form: #F0F4F8;
      --bg-dark: #1A2332;
      --text-main: #1A1A1A;
      --text-secondary: #5A5A5A;
      --text-light: #B0B8C1;
      --text-white: #FFFFFF;
      --success: #0E8C3A;
      --danger: #D93B3B;
      --border-light: #E8ECF1;
      --border-input: #D1D9E0;
      --shadow-sm: 0 2px 12px rgba(0, 0, 0, 0.06);
      --shadow-md: 0 6px 24px rgba(0, 0, 0, 0.10);
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-form: 8px;
      --font-sans: system-ui, -apple-system, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
      --transition: 0.25s ease;
    }

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

    body {
      font-family: var(--font-sans);
      background-color: var(--bg-white);
      color: var(--text-main);
      line-height: 1.5;
      -webkit-font-smoothing: antialiased;
    }

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

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

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

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

    /* 导航 */
    .site-header {
      position: sticky;
      top: 0;
      z-index: 100;
      background: rgba(255, 255, 255, 0.92);
      backdrop-filter: blur(12px);
      height: 72px;
      display: flex;
      align-items: center;
      border-bottom: 1px solid transparent;
      transition: box-shadow 0.3s, border-color 0.3s;
    }

    .site-header.scrolled {
      box-shadow: 0 2px 16px rgba(0, 0, 0, 0.08);
      border-bottom-color: var(--border-light);
    }

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

    .logo {
      font-size: 22px;
      font-weight: 700;
      color: var(--primary);
      display: flex;
      align-items: center;
      gap: 8px;
      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: 700;
      font-size: 18px;
    }

    .nav-links {
      display: flex;
      gap: 32px;
      align-items: center;
    }

    .nav-links a {
      font-size: 16px;
      font-weight: 500;
      color: var(--text-main);
      position: relative;
      padding: 8px 0;
      transition: color var(--transition);
    }

    .nav-links a:hover,
    .nav-links a.active {
      color: var(--primary);
    }
    .nav-links a.active::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 100%;
      height: 2px;
      background: var(--primary);
      border-radius: 1px;
    }

    .hamburger {
      display: none;
      flex-direction: column;
      gap: 6px;
      cursor: pointer;
      background: none;
      border: none;
      width: 32px;
      height: 24px;
      justify-content: center;
      z-index: 110;
    }
    .hamburger span {
      display: block;
      width: 100%;
      height: 2.5px;
      background: var(--text-main);
      border-radius: 2px;
      transition: all 0.3s;
    }

    .mobile-menu {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100vh;
      background: var(--bg-dark);
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      gap: 28px;
      transform: translateX(100%);
      transition: transform 0.3s ease;
      z-index: 105;
    }
    .mobile-menu.open {
      transform: translateX(0);
    }
    .mobile-menu a {
      color: white;
      font-size: 20px;
      font-weight: 500;
    }
    .mobile-close {
      position: absolute;
      top: 24px;
      right: 24px;
      background: none;
      border: none;
      color: white;
      font-size: 28px;
      cursor: pointer;
    }

    @media (max-width: 768px) {
      .nav-links { display: none; }
      .hamburger { display: flex; }
    }

    /* 区块间距 */
    section {
      padding: 100px 0;
    }
    @media (max-width: 768px) {
      section { padding: 60px 0; }
      .container { padding: 0 16px; }
    }

    /* Hero */
    .hero {
      min-height: 90vh;
      display: flex;
      align-items: center;
      background: var(--bg-white);
    }
    .hero-grid {
      display: grid;
      grid-template-columns: 1.1fr 0.9fr;
      gap: 48px;
      align-items: center;
    }
    .hero-text h1 {
      font-size: 36px;
      line-height: 1.3;
      font-weight: 700;
      letter-spacing: -0.5px;
      margin-bottom: 16px;
    }
    .hero-text p {
      font-size: 18px;
      color: var(--text-secondary);
      max-width: 580px;
      margin-bottom: 32px;
    }
    .btn-group {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .btn-primary {
      background: var(--primary);
      color: white;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      border: none;
      cursor: pointer;
      transition: background var(--transition), transform 0.2s;
    }
    .btn-primary:hover {
      background: var(--primary-deep);
      transform: scale(1.02);
    }
    .btn-outline {
      background: transparent;
      border: 1.5px solid var(--primary);
      color: var(--primary);
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      cursor: pointer;
      transition: background var(--transition);
    }
    .btn-outline:hover {
      background: rgba(10,102,194,0.08);
    }
    .hero-illustration img {
      width: 100%;
      border-radius: 24px;
    }
    @media (max-width: 768px) {
      .hero-grid { grid-template-columns: 1fr; text-align: center; }
      .hero-text h1 { font-size: 28px; }
      .btn-group { justify-content: center; }
    }

    /* 数据看板 */
    .dashboard-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
    }
    .stat-card {
      background: var(--bg-light);
      border-radius: var(--radius-card);
      padding: 24px;
      box-shadow: var(--shadow-sm);
      border-top: 4px solid var(--primary);
      transition: all var(--transition);
    }
    .stat-number {
      font-size: 42px;
      font-weight: 700;
      color: var(--primary);
      display: flex;
      align-items: center;
      gap: 8px;
    }
    .trend-up { color: var(--success); font-size: 24px; }
    .trend-down { color: var(--danger); font-size: 24px; }
    .stat-label {
      font-size: 14px;
      color: var(--text-secondary);
      margin-top: 4px;
    }
    @media (max-width: 1024px) {
      .dashboard-grid { grid-template-columns: repeat(2, 1fr); }
    }
    @media (max-width: 520px) {
      .dashboard-grid { grid-template-columns: 1fr; }
    }

    /* 服务矩阵 */
    .services-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .service-item {
      background: white;
      border-radius: var(--radius-card);
      padding: 20px 24px;
      display: flex;
      align-items: center;
      gap: 16px;
      box-shadow: var(--shadow-sm);
      transition: all var(--transition);
      cursor: pointer;
    }
    .service-item:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-md);
    }
    .service-icon {
      font-size: 28px;
      color: var(--primary);
      width: 40px;
      text-align: center;
    }
    .service-content h3 {
      font-size: 20px;
      font-weight: 600;
      margin-bottom: 4px;
    }
    .service-content p {
      font-size: 14px;
      color: var(--text-secondary);
    }
    @media (max-width: 768px) {
      .services-grid { grid-template-columns: 1fr 1fr; }
    }
    @media (max-width: 520px) {
      .services-grid { grid-template-columns: 1fr; }
    }

    /* 案例对比 */
    .compare-wrapper {
      display: grid;
      grid-template-columns: 1fr auto 1fr;
      gap: 32px;
      align-items: center;
    }
    .compare-panel {
      background: var(--bg-light);
      border-radius: var(--radius-card);
      padding: 32px;
    }
    .compare-panel h3 {
      font-size: 22px;
      margin-bottom: 24px;
    }
    .metric-row {
      display: flex;
      justify-content: space-between;
      margin-bottom: 16px;
      font-size: 16px;
    }
    .metric-value {
      font-weight: 700;
    }
    .after .metric-value { color: var(--primary); }
    .divider-arrow {
      font-size: 32px;
      color: var(--accent);
      font-weight: 700;
    }
    @media (max-width: 768px) {
      .compare-wrapper { grid-template-columns: 1fr; }
      .divider-arrow { text-align: center; transform: rotate(90deg); }
    }

    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }
    .faq-item {
      border-bottom: 1px solid var(--border-light);
    }
    .faq-question {
      width: 100%;
      background: none;
      border: none;
      padding: 20px 0;
      font-size: 18px;
      font-weight: 500;
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
      text-align: left;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      background: #FAFBFC;
      padding-left: 16px;
      border-left: 4px solid var(--primary);
      color: var(--text-secondary);
    }
    .faq-item.open .faq-answer {
      max-height: 200px;
      padding: 16px;
    }
    .arrow {
      transition: transform 0.2s;
    }
    .faq-item.open .arrow {
      transform: rotate(180deg);
    }

    /* CTA表单 */
    .contact-section {
      background: var(--bg-form);
      border-radius: 16px;
      padding: 60px 40px;
    }
    .form-grid {
      display: grid;
      gap: 20px;
      max-width: 600px;
      margin: 0 auto;
    }
    .form-grid input, .form-grid textarea {
      width: 100%;
      padding: 14px;
      border: 1px solid var(--border-input);
      border-radius: var(--radius-form);
      font-size: 16px;
    }
    .form-grid textarea {
      height: 120px;
    }
    .btn-submit {
      background: var(--accent);
      color: white;
      font-weight: 700;
      font-size: 18px;
      padding: 16px;
      border: none;
      border-radius: var(--radius-btn);
      cursor: pointer;
      transition: background var(--transition);
    }
    .btn-submit:hover {
      background: var(--accent-deep);
    }

    /* Footer */
    .site-footer {
      background: var(--bg-dark);
      color: var(--text-light);
      padding: 60px 0 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr;
      gap: 48px;
    }
    .footer-brand p {
      margin-top: 12px;
    }
    .footer-links a, .footer-contact a {
      display: block;
      margin-bottom: 12px;
      color: var(--text-light);
    }
    .footer-links a:hover, .footer-contact a:hover {
      color: white;
    }
    .copyright {
      margin-top: 32px;
      padding-top: 24px;
      border-top: 1px solid rgba(255,255,255,0.1);
      font-size: 14px;
    }
    @media (max-width: 768px) {
      .footer-grid { grid-template-columns: 1fr; text-align: center; }
    }