/* roulang page: index */
:root {
      --primary: #4E6EF2;
      --primary-hover: #3A5CE4;
      --primary-light: #EEF1FE;
      --success: #00B578;
      --warning: #FF9F0A;
      --error: #FA5151;
      --text-primary: #1F2329;
      --text-secondary: #86909C;
      --bg-page: #F5F6FA;
      --bg-card: #FFFFFF;
      --border-light: #E5E8EF;
      --shadow-sm: 0 2px 12px rgba(31, 35, 41, 0.08);
      --shadow-md: 0 4px 20px rgba(31, 35, 41, 0.12);
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-pill: 24px;
      --radius-tag: 4px;
      --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      --container-max: 1200px;
      --space-section: 80px;
    }

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

    body {
      font-family: var(--font-sans);
      background-color: var(--bg-page);
      color: var(--text-primary);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
    }

    .container {
      max-width: var(--container-max);
      margin: 0 auto;
      padding: 0 24px;
    }

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

    a {
      text-decoration: none;
      color: inherit;
      transition: color 0.2s ease;
    }

    button, .btn {
      cursor: pointer;
      font-family: inherit;
      border: none;
      background: none;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      transition: all 0.2s ease;
    }

    h1, h2, h3 {
      line-height: 1.3;
      color: var(--text-primary);
    }

    h1 {
      font-size: 36px;
      font-weight: 700;
      letter-spacing: -0.5px;
    }

    h2 {
      font-size: 28px;
      font-weight: 600;
    }

    h3 {
      font-size: 20px;
      font-weight: 500;
    }

    p {
      color: var(--text-secondary);
      max-width: 680px;
    }

    /* 导航 */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      background: rgba(255,255,255,0.95);
      backdrop-filter: blur(10px);
      z-index: 100;
      transition: box-shadow 0.3s ease;
    }
    .header.scrolled {
      box-shadow: 0 2px 12px rgba(0,0,0,0.05);
    }
    .nav {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 68px;
      padding: 0 24px;
      max-width: var(--container-max);
      margin: 0 auto;
    }
    .logo {
      font-size: 22px;
      font-weight: 700;
      color: var(--text-primary);
      display: flex;
      align-items: center;
      gap: 6px;
    }
    .logo span {
      color: var(--primary);
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 32px;
    }
    .nav-links a {
      font-size: 15px;
      font-weight: 500;
      color: var(--text-primary);
      transition: color 0.2s;
      white-space: nowrap;
    }
    .nav-links a:hover {
      color: var(--primary);
    }
    .btn-primary {
      background: var(--primary);
      color: #fff;
      border-radius: var(--radius-btn);
      padding: 10px 22px;
      font-weight: 600;
      font-size: 15px;
      box-shadow: 0 2px 8px rgba(78,110,242,0.2);
    }
    .btn-primary:hover {
      background: var(--primary-hover);
      box-shadow: 0 4px 14px rgba(78,110,242,0.3);
    }
    .btn-outline {
      background: transparent;
      border: 1px solid var(--primary);
      color: var(--primary);
      border-radius: var(--radius-btn);
      padding: 10px 22px;
      font-weight: 600;
      font-size: 15px;
    }
    .btn-outline:hover {
      background: var(--primary-light);
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
      padding: 8px;
    }
    .hamburger span {
      width: 24px;
      height: 2px;
      background: var(--text-primary);
      border-radius: 2px;
      transition: 0.2s;
    }
    .mobile-menu {
      display: none;
      position: fixed;
      top: 68px;
      left: 0;
      width: 100%;
      background: white;
      padding: 24px;
      flex-direction: column;
      gap: 20px;
      box-shadow: var(--shadow-md);
      border-radius: 0 0 16px 16px;
    }
    .mobile-menu a {
      font-size: 18px;
      font-weight: 500;
    }

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

    /* 区块通用 */
    section {
      padding: var(--space-section) 0;
    }

    /* Hero */
    .hero {
      padding: 140px 0 80px;
      display: flex;
      align-items: center;
      gap: 40px;
    }
    .hero-content {
      flex: 1 1 55%;
    }
    .hero-content h1 {
      margin-bottom: 16px;
      font-size: 42px;
    }
    .hero-content p {
      font-size: 18px;
      margin-bottom: 28px;
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .hero-image {
      flex: 1 1 45%;
      display: flex;
      justify-content: center;
      align-items: center;
    }
    .hero-image img {
      max-height: 380px;
      object-fit: contain;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-sm);
    }
    @media (max-width: 768px) {
      .hero {
        flex-direction: column;
        text-align: center;
        padding: 120px 0 60px;
      }
      .hero-content h1 { font-size: 32px; }
      .hero-buttons { justify-content: center; }
    }

    /* 卡片网格 */
    .grid-3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .grid-2 {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 24px;
    }
    .card {
      background: var(--bg-card);
      border-radius: var(--radius-card);
      padding: 32px 28px;
      box-shadow: var(--shadow-sm);
      transition: transform 0.2s ease, box-shadow 0.2s ease;
    }
    .card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-md);
    }
    .card-icon {
      width: 52px;
      height: 52px;
      background: var(--primary-light);
      border-radius: 12px;
      display: flex;
      align-items: center;
      justify-content: center;
      margin-bottom: 20px;
      color: var(--primary);
      font-size: 24px;
    }
    .card h3 {
      margin-bottom: 10px;
    }
    .tag {
      background: rgba(255,159,10,0.15);
      color: var(--warning);
      font-size: 12px;
      font-weight: 600;
      padding: 4px 10px;
      border-radius: var(--radius-tag);
      display: inline-block;
      margin-bottom: 8px;
    }

    /* 服务标签切换 */
    .tabs {
      display: flex;
      gap: 24px;
      margin-bottom: 32px;
      border-bottom: 2px solid var(--border-light);
      flex-wrap: wrap;
    }
    .tab-item {
      padding-bottom: 12px;
      font-weight: 600;
      color: var(--text-secondary);
      cursor: pointer;
      transition: 0.2s;
      border-bottom: 2px solid transparent;
      margin-bottom: -2px;
    }
    .tab-item.active {
      color: var(--primary);
      border-bottom-color: var(--primary);
    }
    .tab-pane {
      display: none;
    }
    .tab-pane.active {
      display: block;
    }

    /* 场景卡片 */
    .scene-card {
      display: flex;
      background: var(--bg-card);
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
      margin-bottom: 24px;
    }
    .scene-text {
      padding: 40px;
      flex: 1;
    }
    .scene-img {
      flex: 1;
      background-size: cover;
      background-position: center;
      min-height: 240px;
    }
    @media (max-width: 768px) {
      .scene-card {
        flex-direction: column;
      }
      .scene-img {
        order: -1;
      }
    }

    /* FAQ */
    .faq-item {
      background: var(--bg-card);
      border-radius: var(--radius-card);
      margin-bottom: 12px;
      box-shadow: var(--shadow-sm);
    }
    .faq-question {
      padding: 20px 28px;
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
      font-size: 16px;
    }
    .faq-answer {
      padding: 0 28px 20px;
      color: var(--text-secondary);
      display: none;
    }
    .faq-item.open .faq-answer {
      display: block;
    }
    .faq-icon {
      transition: 0.2s;
    }
    .faq-item.open .faq-icon {
      transform: rotate(45deg);
    }

    /* CTA区域 */
    .cta-section {
      background: var(--primary-light);
      border-radius: 24px;
      text-align: center;
      padding: 60px 24px;
    }
    .input-group {
      display: flex;
      max-width: 480px;
      margin: 24px auto 0;
      gap: 12px;
    }
    .input-group input {
      flex: 1;
      padding: 14px 20px;
      border-radius: 24px;
      border: 1px solid var(--border-light);
      background: white;
      font-size: 15px;
    }
    .input-group input:focus {
      border-color: var(--primary);
      box-shadow: 0 0 0 3px rgba(78,110,242,0.2);
      outline: none;
    }

    /* 页脚 */
    .footer {
      background: #1F2329;
      color: white;
      padding: 50px 0 20px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 30px;
    }
    .footer a {
      color: #ccc;
      font-size: 14px;
    }
    .copyright {
      text-align: center;
      padding-top: 30px;
      color: #86909C;
      font-size: 14px;
    }

    @media (max-width: 1024px) {
      .grid-3 { grid-template-columns: repeat(2,1fr); }
    }
    @media (max-width: 768px) {
      .grid-3, .grid-2 { grid-template-columns: 1fr; }
      .footer-grid { grid-template-columns: 1fr 1fr; }
      h2 { font-size: 24px; }
      .container { padding: 0 16px; }
    }