/* roulang page: index */
:root {
      --primary: #0EA5E9;
      --secondary: #1E3A5F;
      --accent: #F97316;
      --bg: #F8FAFC;
      --card: #FFFFFF;
      --text: #1E293B;
      --muted: #64748B;
      --border: #E2E8F0;
    }
    *, *::before, *::after { box-sizing: border-box; }
    body {
      font-family: 'PingFang SC', 'Microsoft YaHei', 'Hiragino Sans GB', system-ui, sans-serif;
      background-color: var(--bg);
      color: var(--text);
      line-height: 1.6;
      margin: 0;
      -webkit-font-smoothing: antialiased;
    }
    .font-mono { font-family: 'Inter', 'SF Pro Display', system-ui, sans-serif; }
    .transition-smooth { transition: all 0.25s ease; }
    .nav-blur {
      backdrop-filter: blur(12px);
      background-color: rgba(255,255,255,0.85);
    }
    details summary::-webkit-details-marker { display: none; }
    details summary { list-style: none; }
    .faq-content { max-height: 0; overflow: hidden; transition: max-height 0.4s ease; }
    details[open] .faq-content { max-height: 300px; }