/* roulang page: index */
:root {
      --ng28-primary: #00E5A0;
      --ng28-primary-hover: #00C88A;
      --ng28-dark: #1E1E1E;
      --ng28-body: #4A4A4A;
      --ng28-muted: #8A8A8A;
      --ng28-bg: #F7F5F2;
      --ng28-white: #FFFFFF;
      --ng28-border: #D1D1D1;
      --ng28-light-border: #EFEFEF;
      --ng28-shadow-sm: 0 4px 20px rgba(0,0,0,0.04);
      --ng28-shadow-md: 0 8px 30px rgba(0,0,0,0.08);
      --ng28-radius-card: 12px;
      --ng28-radius-btn: 8px;
      --ng28-radius-img: 16px;
      --ng28-font-cn: 'PingFang SC', 'Microsoft YaHei', 'Hiragino Sans GB', 'Noto Sans SC', sans-serif;
      --ng28-font-en: 'Inter', 'SF Pro Display', sans-serif;
      --ng28-max-width: 1280px;
      --ng28-gutter: 24px;
      --ng28-section-gap: 100px;
    }

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

    body {
      font-family: var(--ng28-font-cn);
      background-color: var(--ng28-bg);
      color: var(--ng28-body);
      line-height: 1.6;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }

    .container {
      max-width: var(--ng28-max-width);
      margin: 0 auto;
      padding: 0 20px;
    }

    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;
    }

    h1, h2, h3, h4 {
      font-family: var(--ng28-font-cn);
      color: var(--ng28-dark);
      line-height: 1.3;
    }

    h1 {
      font-size: 48px;
      font-weight: 700;
      letter-spacing: -0.5px;
      line-height: 1.2;
    }

    h2 {
      font-size: 36px;
      font-weight: 600;
    }

    h3 {
      font-size: 24px;
      font-weight: 600;
    }

    .section-title {
      margin-bottom: 16px;
    }

    .section-desc {
      color: var(--ng28-muted);
      font-size: 18px;
      max-width: 640px;
      margin: 0 auto 48px;
      text-align: center;
    }

    /* 按钮系统 */
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 14px 32px;
      border-radius: var(--ng28-radius-btn);
      font-weight: 600;
      font-size: 16px;
      transition: all 0.25s ease;
      border: 2px solid transparent;
      white-space: nowrap;
    }

    .btn-primary {
      background-color: var(--ng28-primary);
      color: var(--ng28-dark);
      border-color: var(--ng28-primary);
    }
    .btn-primary:hover {
      background-color: var(--ng28-primary-hover);
      border-color: var(--ng28-primary-hover);
      transform: translateY(-2px);
      box-shadow: 0 8px 16px rgba(0,229,160,0.25);
    }

    .btn-outline {
      background: transparent;
      border: 2px solid var(--ng28-dark);
      color: var(--ng28-dark);
    }
    .btn-outline:hover {
      background: var(--ng28-dark);
      color: var(--ng28-white);
      transform: translateY(-2px);
    }

    /* 导航 */
    .site-header {
      background: var(--ng28-white);
      position: sticky;
      top: 0;
      z-index: 50;
      box-shadow: 0 2px 12px rgba(0,0,0,0.04);
    }

    .brand-row {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 48px;
      border-bottom: 1px solid var(--ng28-light-border);
      padding: 0 20px;
    }

    .logo {
      font-family: var(--ng28-font-en);
      font-weight: 700;
      font-size: 22px;
      color: var(--ng28-dark);
      letter-spacing: 1px;
      display: flex;
      align-items: center;
      gap: 8px;
    }
    .logo span {
      color: var(--ng28-primary);
      font-weight: 800;
    }

    .brand-actions {
      display: flex;
      align-items: center;
      gap: 24px;
      color: var(--ng28-muted);
    }
    .search-trigger {
      display: flex;
      align-items: center;
      gap: 6px;
      font-size: 15px;
      cursor: pointer;
    }

    .channel-bar {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 44px;
      padding: 0 20px;
    }
    .nav-links {
      display: flex;
      gap: 32px;
      list-style: none;
    }
    .nav-links a {
      font-size: 15px;
      font-weight: 500;
      color: var(--ng28-dark);
      padding: 8px 0;
      border-bottom: 2px solid transparent;
      transition: border-color 0.2s, color 0.2s;
    }
    .nav-links a:hover,
    .nav-links a.active {
      border-bottom-color: var(--ng28-primary);
      color: var(--ng28-dark);
    }

    .mobile-menu-btn {
      display: none;
      background: none;
      border: none;
      font-size: 28px;
      color: var(--ng28-dark);
    }

    /* Hero */
    .hero {
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 40px;
      padding: 60px 0;
      background-color: var(--ng28-bg);
      background-image: radial-gradient(circle at 20% 30%, rgba(0,229,160,0.03) 0%, transparent 40%);
    }
    .hero-content {
      flex: 1 1 50%;
    }
    .hero-content h1 {
      margin-bottom: 20px;
    }
    .hero-content p {
      font-size: 18px;
      color: var(--ng28-body);
      margin-bottom: 32px;
      line-height: 1.7;
      max-width: 480px;
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .hero-image {
      flex: 1 1 45%;
      background: var(--ng28-white);
      border-radius: var(--ng28-radius-img);
      overflow: hidden;
      box-shadow: var(--ng28-shadow-md);
    }
    .hero-image img {
      width: 100%;
      height: auto;
      object-fit: cover;
      aspect-ratio: 4/3;
    }

    /* 卡片通用 */
    .card {
      background: var(--ng28-white);
      border-radius: var(--ng28-radius-card);
      box-shadow: var(--ng28-shadow-sm);
      transition: all 0.3s ease;
    }
    .card:hover {
      box-shadow: var(--ng28-shadow-md);
      transform: translateY(-4px);
    }

    /* 核心功能 */
    .features-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
      margin-top: 32px;
    }
    .feature-card {
      padding: 32px;
      text-align: left;
      display: flex;
      flex-direction: column;
      gap: 16px;
    }
    .feature-icon {
      font-size: 40px;
      color: var(--ng28-primary);
      transition: transform 0.2s;
    }
    .feature-card:hover .feature-icon {
      transform: scale(1.05);
    }

    /* 使用场景 */
    .scenario-row {
      display: flex;
      align-items: center;
      gap: 60px;
      margin-bottom: 80px;
    }
    .scenario-row.reverse {
      flex-direction: row-reverse;
    }
    .scenario-text {
      flex: 1;
    }
    .scenario-text h3 {
      margin-bottom: 16px;
    }
    .scenario-image {
      flex: 1;
      border-radius: var(--ng28-radius-img);
      overflow: hidden;
      background: var(--ng28-white);
      box-shadow: var(--ng28-shadow-sm);
    }
    .scenario-image img {
      width: 100%;
      aspect-ratio: 16/10;
      object-fit: cover;
    }

    /* 案例卡片 */
    .cases-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .case-card {
      overflow: hidden;
    }
    .case-img {
      width: 100%;
      aspect-ratio: 16/9;
      object-fit: cover;
      border-radius: var(--ng28-radius-card) var(--ng28-radius-card) 0 0;
    }
    .case-body {
      padding: 24px;
    }
    .case-tag {
      display: inline-block;
      background: #E6FFF6;
      color: #00855A;
      font-size: 13px;
      padding: 4px 12px;
      border-radius: 20px;
      margin-bottom: 12px;
    }
    .case-stat {
      font-size: 28px;
      font-weight: 700;
      color: var(--ng28-primary);
      margin: 8px 0;
    }

    /* 价格卡片 */
    .pricing-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
      align-items: start;
    }
    .pricing-card {
      padding: 32px;
      text-align: center;
    }
    .pricing-card.featured {
      border: 2px solid var(--ng28-primary);
      background: #E6FFF6;
    }
    .price {
      font-size: 48px;
      font-weight: 700;
      color: var(--ng28-dark);
      margin: 16px 0;
    }

    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }
    .faq-item {
      background: var(--ng28-white);
      border-radius: var(--ng28-radius-card);
      margin-bottom: 12px;
      overflow: hidden;
    }
    .faq-question {
      padding: 20px 24px;
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-weight: 500;
      cursor: pointer;
      background: var(--ng28-white);
    }
    .faq-answer {
      padding: 0 24px 20px;
      color: var(--ng28-body);
      display: none;
    }
    .faq-item.open .faq-answer {
      display: block;
    }

    /* CTA 横幅 */
    .cta-banner {
      background: var(--ng28-dark);
      color: white;
      border-radius: var(--ng28-radius-card);
      padding: 60px 40px;
      text-align: center;
      margin: 0 20px;
    }
    .cta-banner h2 {
      color: white;
    }

    /* 页脚 */
    .site-footer {
      background: var(--ng28-white);
      padding: 60px 0 0;
      margin-top: 80px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
      padding-bottom: 40px;
    }
    .copyright {
      background: var(--ng28-dark);
      color: var(--ng28-muted);
      text-align: center;
      padding: 16px 20px;
      font-size: 14px;
    }

    @media (max-width: 1024px) {
      h1 { font-size: 40px; }
      .features-grid, .cases-grid, .pricing-grid { grid-template-columns: repeat(2, 1fr); }
      .hero { flex-direction: column; }
      .footer-grid { grid-template-columns: 1fr 1fr; }
    }

    @media (max-width: 768px) {
      h1 { font-size: 36px; }
      h2 { font-size: 28px; }
      .nav-links { display: none; }
      .mobile-menu-btn { display: block; }
      .features-grid, .cases-grid, .pricing-grid { grid-template-columns: 1fr; }
      .scenario-row, .scenario-row.reverse { flex-direction: column; }
      .hero-buttons { flex-direction: column; align-items: flex-start; }
      .footer-grid { grid-template-columns: 1fr; }
      :root { --ng28-section-gap: 60px; }
      section { margin-bottom: 60px; }
    }