/* roulang page: index */
:root {
      --panda-black: #1A1A1A;
      --bamboo-green: #00A86B;
      --bg-light: #F7F9FC;
      --card-white: #FFFFFF;
      --text-primary: #2C3E50;
      --text-secondary: #5A6C7D;
      --accent-light-green: #E8F5E9;
      --border-light: #E1E8EE;
      --shadow-card: 0 2px 12px rgba(0,0,0,0.04), 0 1px 2px rgba(0,0,0,0.06);
      --shadow-hover: 0 8px 24px rgba(0,0,0,0.08), 0 2px 6px rgba(0,0,0,0.04);
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-tag: 6px;
      --transition-default: all 0.25s ease;
      --container-max: 1200px;
    }

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

    body {
      font-family: system-ui, -apple-system, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
      background-color: var(--bg-light);
      color: var(--text-primary);
      line-height: 1.7;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }

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

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

    button, .btn {
      cursor: pointer;
      font-family: inherit;
      border: none;
      outline: none;
      transition: var(--transition-default);
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 6px;
    }

    .container {
      max-width: var(--container-max);
      margin-left: auto;
      margin-right: auto;
      padding-left: 20px;
      padding-right: 20px;
    }

    /* 导航 */
    .main-header {
      position: sticky;
      top: 0;
      background: white;
      box-shadow: 0 1px 4px rgba(0,0,0,0.04);
      height: 64px;
      z-index: 100;
      display: flex;
      align-items: center;
    }
    .nav-container {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
    }
    .logo {
      font-weight: 700;
      font-size: 1.5rem;
      color: var(--panda-black);
      display: flex;
      align-items: center;
      gap: 8px;
    }
    .logo i {
      color: var(--bamboo-green);
      font-size: 1.8rem;
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 32px;
    }
    .nav-links a {
      font-weight: 500;
      font-size: 0.95rem;
      color: var(--text-primary);
      transition: color 0.2s;
    }
    .nav-links a:hover {
      color: var(--bamboo-green);
    }
    .nav-cta {
      background: var(--bamboo-green);
      color: white;
      padding: 10px 24px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 0.9rem;
    }
    .nav-cta:hover {
      background: #008F5A;
      transform: translateY(-1px);
    }
    .hamburger {
      display: none;
      font-size: 1.8rem;
      background: none;
      border: none;
      color: var(--panda-black);
      cursor: pointer;
    }
    .mobile-menu {
      display: none;
      position: fixed;
      top: 64px;
      left: 0;
      width: 100%;
      height: calc(100vh - 64px);
      background: white;
      flex-direction: column;
      gap: 28px;
      padding: 40px 20px;
      z-index: 99;
      align-items: center;
      overflow-y: auto;
    }
    .mobile-menu.active {
      display: flex;
    }
    .mobile-menu a {
      font-size: 1.2rem;
      font-weight: 500;
    }
    .mobile-menu .nav-cta {
      width: 100%;
      text-align: center;
      margin-top: 20px;
      padding: 14px 20px;
    }

    /* Hero */
    .hero {
      background-color: var(--bg-light);
      min-height: 560px;
      display: flex;
      align-items: center;
      padding: 60px 0;
      position: relative;
      overflow: hidden;
    }
    .hero::after {
      content: "";
      position: absolute;
      right: -20px;
      top: 30px;
      width: 280px;
      height: 280px;
      background: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100" opacity="0.08"><path d="M50 10C30 10 20 25 20 40c0 10 5 18 12 23-3 2-6 4-8 7 3-1 6-2 9-2 8 0 14 4 18 10 4-6 10-10 18-10 3 0 6 1 9 2-2-3-5-5-8-7 7-5 12-13 12-23C80 25 70 10 50 10z" fill="%231A1A1A"/></svg>') no-repeat;
      background-size: contain;
      pointer-events: none;
    }
    .hero-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 40px;
      align-items: center;
    }
    .hero-content h1 {
      font-size: 2.8rem;
      font-weight: 700;
      line-height: 1.2;
      color: var(--panda-black);
      margin-bottom: 16px;
      letter-spacing: -0.5px;
    }
    .hero-subtitle {
      font-size: 1.1rem;
      color: var(--text-secondary);
      margin-bottom: 28px;
      max-width: 480px;
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .btn-primary {
      background: var(--bamboo-green);
      color: white;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 1rem;
      box-shadow: 0 4px 10px rgba(0,168,107,0.2);
    }
    .btn-primary:hover {
      background: #008F5A;
      transform: translateY(-2px);
      box-shadow: 0 8px 18px rgba(0,168,107,0.3);
    }
    .btn-secondary {
      background: transparent;
      border: 1.5px solid var(--panda-black);
      color: var(--panda-black);
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 1rem;
    }
    .btn-secondary:hover {
      background: var(--panda-black);
      color: white;
      transform: translateY(-2px);
    }
    .hero-image img {
      border-radius: 24px;
      box-shadow: 0 20px 35px rgba(0,0,0,0.08);
      width: 100%;
      max-width: 380px;
      margin: 0 auto;
      background: #fff;
    }

    /* Sections */
    .section {
      padding: 100px 0;
    }
    .section-title {
      font-size: 2rem;
      font-weight: 600;
      color: var(--panda-black);
      margin-bottom: 16px;
      line-height: 1.3;
    }
    .section-desc {
      color: var(--text-secondary);
      margin-bottom: 40px;
      max-width: 680px;
    }

    /* 核心优势 不对称布局 */
    .advantage-grid {
      display: grid;
      grid-template-columns: 2fr 1fr;
      gap: 50px;
      align-items: start;
    }
    .advantage-left h2 {
      font-size: 2rem;
      font-weight: 600;
    }
    .advantage-list {
      display: flex;
      flex-direction: column;
      gap: 24px;
    }
    .advantage-item {
      display: flex;
      gap: 14px;
      padding-bottom: 18px;
      border-bottom: 1px solid var(--border-light);
    }
    .advantage-item i {
      color: var(--bamboo-green);
      font-size: 1.4rem;
      margin-top: 4px;
    }
    .advantage-item h3 {
      font-size: 1.2rem;
      font-weight: 600;
      margin-bottom: 4px;
    }

    /* 功能分组 左右交替 */
    .feature-row {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 60px;
      align-items: center;
      margin-bottom: 80px;
    }
    .feature-row.reverse {
      direction: rtl;
    }
    .feature-row.reverse .feature-text {
      direction: ltr;
    }
    .feature-image img {
      border-radius: 16px;
      box-shadow: var(--shadow-card);
      width: 100%;
    }
    .feature-text h3 {
      font-size: 1.8rem;
      font-weight: 600;
      margin-bottom: 16px;
    }
    .feature-list {
      list-style: none;
      margin: 18px 0 24px;
    }
    .feature-list li {
      display: flex;
      align-items: center;
      gap: 10px;
      margin-bottom: 10px;
      color: var(--text-primary);
    }
    .feature-list i {
      color: var(--bamboo-green);
    }
    .text-link {
      color: var(--bamboo-green);
      font-weight: 600;
      display: inline-flex;
      align-items: center;
      gap: 4px;
    }
    .text-link:hover {
      text-decoration: underline;
    }

    /* 场景卡片 */
    .cards-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .scene-card {
      background: var(--card-white);
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-card);
      overflow: hidden;
      transition: var(--transition-default);
    }
    .scene-card:hover {
      box-shadow: var(--shadow-hover);
    }
    .scene-card img {
      aspect-ratio: 16/9;
      object-fit: cover;
      transition: transform 0.3s;
    }
    .scene-card:hover img {
      transform: scale(1.02);
    }
    .scene-card-content {
      padding: 20px;
    }
    .scene-card h3 {
      font-size: 1.3rem;
      margin-bottom: 8px;
    }

    /* 数据面板 */
    .stats-band {
      background: var(--accent-light-green);
      padding: 60px 0;
    }
    .stats-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 30px;
      text-align: center;
    }
    .stat-number {
      font-size: 2.4rem;
      font-weight: 700;
      color: var(--panda-black);
    }
    .stat-label {
      font-size: 0.9rem;
      color: var(--text-secondary);
      margin-top: 6px;
    }

    /* 价格 */
    .pricing-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
      align-items: start;
    }
    .pricing-card {
      background: white;
      border-radius: var(--radius-card);
      padding: 32px 24px;
      box-shadow: var(--shadow-card);
      text-align: center;
      transition: var(--transition-default);
      position: relative;
      border: 2px solid transparent;
    }
    .pricing-card.featured {
      border-color: var(--bamboo-green);
    }
    .badge {
      background: var(--bamboo-green);
      color: white;
      font-size: 0.75rem;
      padding: 4px 12px;
      border-radius: 20px;
      position: absolute;
      top: -12px;
      left: 50%;
      transform: translateX(-50%);
      font-weight: 600;
    }
    .price {
      font-size: 2.5rem;
      font-weight: 700;
      color: var(--panda-black);
      margin: 20px 0 12px;
    }
    .pricing-features {
      text-align: left;
      margin: 24px 0;
      list-style: none;
    }
    .pricing-features li {
      padding: 8px 0;
      display: flex;
      align-items: center;
      gap: 8px;
    }
    .btn-block {
      width: 100%;
    }

    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }
    .faq-item {
      border-bottom: 1px solid var(--border-light);
      padding: 18px 0;
    }
    .faq-question {
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-weight: 600;
      font-size: 1.1rem;
      cursor: pointer;
      background: none;
      border: none;
      width: 100%;
      text-align: left;
      color: var(--panda-black);
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      color: var(--text-secondary);
      padding-right: 20px;
    }
    .faq-item.active .faq-answer {
      max-height: 150px;
      margin-top: 12px;
    }
    .faq-item.active .faq-question {
      color: var(--bamboo-green);
    }

    /* 最终CTA */
    .cta-banner {
      background: var(--panda-black);
      padding: 80px 0;
      text-align: center;
      color: white;
    }
    .cta-banner h2 {
      font-size: 2.2rem;
      font-weight: 700;
      color: white;
      margin-bottom: 14px;
    }
    .cta-banner p {
      color: #ccc;
      margin-bottom: 30px;
    }

    /* Footer */
    .main-footer {
      background: var(--panda-black);
      color: #CCCCCC;
      padding: 60px 0 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 1fr 2fr;
      gap: 40px;
    }
    .footer-links {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 20px;
    }
    .footer-links h4 {
      color: white;
      margin-bottom: 12px;
    }
    .footer-links a {
      display: block;
      color: #CCCCCC;
      margin-bottom: 8px;
      font-size: 0.9rem;
    }
    .footer-links a:hover {
      color: white;
    }
    .copyright {
      margin-top: 40px;
      border-top: 1px solid #333;
      padding-top: 20px;
      text-align: center;
      font-size: 0.85rem;
    }

    @media (max-width: 1024px) {
      .hero-grid, .feature-row, .advantage-grid {
        grid-template-columns: 1fr;
        gap: 40px;
      }
      .hero-image img {
        max-width: 280px;
      }
      .feature-row.reverse {
        direction: ltr;
      }
      .cards-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .pricing-grid {
        grid-template-columns: 1fr 1fr;
      }
    }
    @media (max-width: 768px) {
      .nav-links { display: none; }
      .hamburger { display: block; }
      .section { padding: 70px 0; }
      .cards-grid, .pricing-grid, .stats-grid {
        grid-template-columns: 1fr;
      }
      .footer-grid {
        grid-template-columns: 1fr;
      }
      .hero-content h1 {
        font-size: 2.2rem;
      }
    }
    @media (max-width: 520px) {
      .hero-buttons .btn {
        width: 100%;
      }
      .btn-primary, .btn-secondary {
        width: 100%;
      }
    }