/* roulang page: index */
:root {
      --primary: #2E7D32;
      --primary-hover: #1B5E20;
      --accent: #F9A825;
      --bg: #F5F6FA;
      --white: #FFFFFF;
      --text: #1F2329;
      --text-light: #86909C;
      --border: #E8EAED;
      --shadow-card: 0 2px 12px rgba(0,0,0,0.06);
      --shadow-hover: 0 6px 20px rgba(0,0,0,0.1);
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-input: 8px;
      --radius-tag: 16px;
      --transition: 200ms ease;
      --font-sans: 'PingFang SC', 'Microsoft YaHei', system-ui, -apple-system, sans-serif;
    }

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

    html {
      scroll-behavior: smooth;
      font-size: 16px;
    }

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

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

    a {
      text-decoration: none;
      color: inherit;
      transition: color var(--transition);
    }

    ul {
      list-style: none;
    }

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

    /* 按钮规范 */
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 12px 24px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 16px;
      transition: all var(--transition);
      cursor: pointer;
      border: 1.5px solid transparent;
      background: transparent;
      line-height: 1.2;
    }

    .btn-primary {
      background-color: var(--primary);
      color: var(--white);
      border-color: var(--primary);
    }

    .btn-primary:hover {
      background-color: var(--primary-hover);
      border-color: var(--primary-hover);
    }

    .btn-outline {
      background-color: transparent;
      color: var(--primary);
      border-color: var(--primary);
    }

    .btn-outline:hover {
      background-color: #E8F5E9;
    }

    .btn-lg {
      padding: 14px 32px;
      font-size: 18px;
    }

    /* 导航 Header */
    .site-header {
      position: sticky;
      top: 0;
      z-index: 100;
      background-color: var(--white);
      border-bottom: 1px solid var(--border);
      height: 64px;
      display: flex;
      align-items: center;
    }

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

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

    .logo i {
      font-size: 28px;
      color: var(--primary);
    }

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

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

    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 2px;
      background-color: var(--primary);
      transition: width var(--transition);
    }

    .nav-links a:hover,
    .nav-links a.active {
      color: var(--primary);
    }

    .nav-links a:hover::after,
    .nav-links a.active::after {
      width: 100%;
    }

    .hamburger {
      display: none;
      background: none;
      border: none;
      font-size: 24px;
      color: var(--text);
      cursor: pointer;
    }

    .mobile-menu {
      position: fixed;
      top: 0;
      right: -100%;
      width: 80%;
      max-width: 320px;
      height: 100vh;
      background: var(--white);
      box-shadow: -2px 0 20px rgba(0,0,0,0.1);
      z-index: 200;
      transition: right 0.3s ease;
      padding: 24px;
      display: flex;
      flex-direction: column;
    }

    .mobile-menu.open {
      right: 0;
    }

    .mobile-menu .close-btn {
      align-self: flex-end;
      background: none;
      border: none;
      font-size: 28px;
      color: var(--text);
      cursor: pointer;
    }

    .mobile-nav-links {
      display: flex;
      flex-direction: column;
      gap: 24px;
      margin-top: 48px;
    }

    .mobile-nav-links a {
      font-size: 18px;
      font-weight: 500;
    }

    /* 区块间距 */
    section {
      padding: 100px 0;
    }

    /* Hero */
    .hero {
      background-color: var(--bg);
      display: flex;
      align-items: center;
      min-height: 85vh;
    }

    .hero-grid {
      display: flex;
      align-items: center;
      gap: 60px;
    }

    .hero-content {
      flex: 1;
    }

    .hero-content h1 {
      font-size: 48px;
      font-weight: 700;
      line-height: 1.2;
      margin-bottom: 20px;
      color: var(--text);
    }

    .hero-content .subtitle {
      font-size: 18px;
      color: var(--text-light);
      margin-bottom: 32px;
    }

    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }

    .hero-image {
      flex: 1;
      text-align: right;
    }

    .hero-image img {
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-hover);
      width: 100%;
      max-width: 540px;
      margin-left: auto;
    }

    /* 区块标题 */
    .section-title {
      text-align: center;
      margin-bottom: 60px;
    }

    .section-title h2 {
      font-size: 32px;
      font-weight: 700;
      margin-bottom: 16px;
    }

    .section-title p {
      font-size: 16px;
      color: var(--text-light);
      max-width: 600px;
      margin: 0 auto;
    }

    /* 功能卡片 */
    .features-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }

    .feature-card {
      background: var(--white);
      padding: 32px 24px;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-card);
      transition: all var(--transition);
      text-align: center;
    }

    .feature-card:hover {
      box-shadow: var(--shadow-hover);
      transform: translateY(-4px);
    }

    .feature-icon {
      width: 64px;
      height: 64px;
      background: #E8F5E9;
      border-radius: 12px;
      display: flex;
      align-items: center;
      justify-content: center;
      margin: 0 auto 24px;
    }

    .feature-icon i {
      font-size: 28px;
      color: var(--primary);
    }

    .feature-card h3 {
      font-size: 20px;
      margin-bottom: 12px;
      font-weight: 600;
    }

    .feature-card p {
      color: var(--text-light);
      font-size: 16px;
    }

    /* 场景卡片 */
    .scenarios-grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 24px;
    }

    .scenario-card {
      background: var(--white);
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-card);
      display: flex;
      overflow: hidden;
      transition: var(--transition);
    }

    .scenario-card:hover {
      box-shadow: var(--shadow-hover);
    }

    .scenario-img {
      width: 40%;
      object-fit: cover;
    }

    .scenario-text {
      padding: 32px;
      display: flex;
      flex-direction: column;
      justify-content: center;
    }

    .scenario-text h3 {
      font-size: 22px;
      margin-bottom: 12px;
    }

    .scenario-text p {
      color: var(--text-light);
    }

    /* 案例数据 */
    .cases-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }

    .case-card {
      background: var(--white);
      padding: 32px 24px;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-card);
      text-align: center;
    }

    .case-number {
      font-size: 40px;
      font-weight: 700;
      color: var(--accent);
      margin-bottom: 12px;
    }

    .case-card h3 {
      font-size: 20px;
      margin-bottom: 12px;
    }

    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }

    .faq-item {
      border-bottom: 1px solid var(--border);
    }

    .faq-question {
      width: 100%;
      background: var(--white);
      border: none;
      padding: 20px 16px;
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-size: 16px;
      font-weight: 600;
      cursor: pointer;
      text-align: left;
      color: var(--text);
      transition: background var(--transition);
    }

    .faq-question i {
      color: var(--primary);
      transition: transform 0.2s;
    }

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease, padding 0.3s;
      background: #F5F6FA;
      padding: 0 16px;
      color: var(--text);
    }

    .faq-answer.open {
      max-height: 200px;
      padding: 16px;
    }

    /* CTA 尾屏 */
    .cta-section {
      background-color: #E8F5E9;
      text-align: center;
    }

    .cta-content h2 {
      font-size: 32px;
      margin-bottom: 16px;
    }

    .cta-content p {
      color: var(--text-light);
      margin-bottom: 32px;
    }

    .cta-buttons {
      display: flex;
      gap: 16px;
      justify-content: center;
    }

    /* Footer */
    .site-footer {
      background: var(--white);
      border-top: 1px solid var(--border);
      padding: 60px 0 30px;
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
    }

    .footer-col h4 {
      font-size: 18px;
      margin-bottom: 20px;
      color: var(--text);
    }

    .footer-col p, .footer-col a {
      font-size: 14px;
      color: var(--text-light);
      line-height: 2;
      display: block;
    }

    .footer-col a:hover {
      color: var(--primary);
    }

    .social-icons i {
      font-size: 20px;
      margin-right: 16px;
      color: var(--text-light);
      transition: color var(--transition);
    }

    .social-icons i:hover {
      color: var(--primary);
    }

    .copyright {
      text-align: center;
      margin-top: 40px;
      font-size: 14px;
      color: var(--text-light);
    }

    /* 响应式 */
    @media (max-width: 992px) {
      .features-grid,
      .cases-grid {
        grid-template-columns: repeat(2, 1fr);
      }

      .hero-grid {
        flex-direction: column;
        text-align: center;
        gap: 40px;
      }

      .hero-image img {
        margin: 0 auto;
      }

      .footer-grid {
        grid-template-columns: repeat(2, 1fr);
      }
    }

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

      .hamburger {
        display: block;
      }

      .hero-content h1 {
        font-size: 36px;
      }

      .scenarios-grid {
        grid-template-columns: 1fr;
      }

      .scenario-card {
        flex-direction: column;
      }

      .scenario-img {
        width: 100%;
        height: 200px;
      }
    }

    @media (max-width: 576px) {
      .container {
        padding: 0 20px;
      }

      .features-grid,
      .cases-grid {
        grid-template-columns: 1fr;
      }

      .hero-content h1 {
        font-size: 30px;
      }

      .btn-lg {
        padding: 12px 20px;
      }

      .footer-grid {
        grid-template-columns: 1fr;
        gap: 30px;
      }

      section {
        padding: 70px 0;
      }
    }

    .overlay {
      position: fixed;
      inset: 0;
      background: rgba(0,0,0,0.3);
      z-index: 150;
      display: none;
    }

    .overlay.show {
      display: block;
    }