/* roulang page: index */
:root {
      --primary: #0D7C66;
      --primary-dark: #0A4F5E;
      --accent: #F5A623;
      --accent-hover: #D4891E;
      --bg: #F7F5F2;
      --card: #FFFFFF;
      --text: #2D2D2D;
      --text-secondary: #6B7280;
      --border: #E5E7EB;
      --radius-lg: 16px;
      --radius-md: 12px;
      --shadow-sm: 0 4px 20px rgba(0,0,0,0.04);
      --shadow-md: 0 8px 30px rgba(0,0,0,0.08);
      --transition: 200ms ease;
    }
    * {
      box-sizing: border-box;
    }
    body {
      margin: 0;
      font-family: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "Noto Sans SC", sans-serif;
      background-color: var(--bg);
      color: var(--text);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    a {
      color: inherit;
      text-decoration: none;
      transition: color var(--transition);
    }
    a:hover {
      color: var(--accent);
    }
    button {
      font-family: inherit;
    }
    .container {
      max-width: 1280px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 24px;
      padding-right: 24px;
    }
    /* 导航 */
    .navbar {
      position: sticky;
      top: 0;
      z-index: 50;
      background: var(--card);
      border-bottom: 1px solid var(--border);
      backdrop-filter: blur(4px);
    }
    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      padding-top: 16px;
      padding-bottom: 16px;
    }
    .logo {
      font-weight: 700;
      font-size: 24px;
      color: var(--primary);
      letter-spacing: 1px;
      white-space: nowrap;
    }
    .nav-links {
      display: flex;
      gap: 32px;
      align-items: center;
    }
    .nav-links a {
      font-weight: 500;
      font-size: 16px;
      color: var(--text);
      transition: color var(--transition);
      white-space: nowrap;
    }
    .nav-links a:hover {
      color: var(--accent);
    }
    .menu-toggle {
      display: none;
      background: none;
      border: none;
      font-size: 28px;
      color: var(--primary);
      cursor: pointer;
    }
    /* 移动导航 */
    .mobile-menu {
      display: none;
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background: var(--bg);
      z-index: 100;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      gap: 32px;
      transition: opacity 0.3s;
    }
    .mobile-menu.open {
      display: flex;
    }
    .mobile-menu .close-btn {
      position: absolute;
      top: 24px;
      right: 24px;
      font-size: 32px;
      background: none;
      border: none;
      color: var(--primary);
      cursor: pointer;
    }
    /* Hero */
    .hero {
      background: linear-gradient(135deg, #0D7C66 0%, #0A4F5E 100%);
      color: white;
      padding-top: 80px;
      padding-bottom: 80px;
    }
    /* 卡片基础 */
    .card {
      background: var(--card);
      border-radius: var(--radius-lg);
      padding: 32px;
      box-shadow: var(--shadow-sm);
      transition: box-shadow var(--transition), transform var(--transition);
    }
    .card:hover {
      box-shadow: var(--shadow-md);
      transform: translateY(-4px);
    }
    /* 按钮 */
    .btn-primary {
      background: var(--accent);
      color: white;
      font-weight: 600;
      padding: 12px 32px;
      border-radius: var(--radius-lg);
      display: inline-block;
      text-align: center;
      transition: background var(--transition), transform var(--transition);
      border: none;
      cursor: pointer;
    }
    .btn-primary:hover {
      background: var(--accent-hover);
      transform: scale(1.05);
      color: white;
    }
    .btn-secondary {
      background: transparent;
      color: var(--primary);
      border: 2px solid var(--primary);
      font-weight: 600;
      padding: 12px 32px;
      border-radius: var(--radius-lg);
      display: inline-block;
      text-align: center;
      transition: background var(--transition), color var(--transition);
      cursor: pointer;
    }
    .btn-secondary:hover {
      background: rgba(13,124,102,0.1);
      color: var(--primary);
    }
    .btn-light {
      background: white;
      color: var(--primary);
      font-weight: 600;
      padding: 12px 32px;
      border-radius: var(--radius-lg);
      display: inline-block;
      border: none;
      cursor: pointer;
    }
    /* 数据徽章 */
    .badge-data {
      background: rgba(245,166,35,0.1);
      color: var(--accent);
      font-weight: 700;
      font-size: 32px;
      line-height: 1.2;
      padding: 4px 12px;
      border-radius: 12px;
      display: inline-block;
    }
    /* FAQ */
    .faq-item {
      border-bottom: 1px solid var(--border);
      padding: 20px 0;
    }
    .faq-question {
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-weight: 600;
      font-size: 18px;
      cursor: pointer;
      background: none;
      border: none;
      width: 100%;
      text-align: left;
      color: var(--text);
      padding: 0;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease, padding 0.3s;
      color: var(--text-secondary);
    }
    .faq-answer.open {
      max-height: 200px;
      padding-top: 16px;
    }
    /* 页脚 */
    .footer {
      background: #0A4F5E;
      color: rgba(255,255,255,0.8);
      padding: 48px 0 24px;
    }
    .footer a {
      color: rgba(255,255,255,0.8);
    }
    .footer a:hover {
      color: var(--accent);
    }
    @media (max-width: 768px) {
      .nav-links {
        display: none;
      }
      .menu-toggle {
        display: block;
      }
      .hero {
        padding-top: 48px;
        padding-bottom: 48px;
      }
      .container {
        padding-left: 16px;
        padding-right: 16px;
      }
      h1 {
        font-size: 32px !important;
      }
      h2 {
        font-size: 28px !important;
      }
    }