/* roulang page: index */
:root {
      --color-primary: #1F2937;
      --color-primary-dark: #111827;
      --color-accent: #D97706;
      --color-accent-hover: #B45309;
      --color-bg-light: #F9FAFB;
      --color-bg-subtle: #F3F4F6;
      --color-text-main: #1F2937;
      --color-text-muted: #4B5563;
      --color-border: #E5E7EB;
    }
    html {
      scroll-behavior: smooth;
      font-family: system-ui, -apple-system, "PingFang SC", "Microsoft YaHei", "Segoe UI", sans-serif;
    }
    body {
      background-color: var(--color-bg-light);
      color: var(--color-text-main);
      line-height: 1.75;
      letter-spacing: 0.01em;
    }
    .custom-container {
      max-width: 1200px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 1.25rem;
      padding-right: 1.25rem;
    }
    .section-py {
      padding-top: 4.5rem;
      padding-bottom: 4.5rem;
    }
    @media (max-width: 768px) {
      .section-py {
        padding-top: 3rem;
        padding-bottom: 3rem;
      }
    }
    .btn-accent {
      background-color: var(--color-accent);
      color: #ffffff;
      transition: all 0.2s ease-in-out;
    }
    .btn-accent:hover {
      background-color: var(--color-accent-hover);
      box-shadow: 0 4px 12px rgba(217, 119, 6, 0.25);
    }
    .card-solid {
      background: #ffffff;
      border: 1px solid var(--color-border);
      border-radius: 0.75rem;
      box-shadow: 0 1px 3px rgba(0,0,0,0.05);
      transition: transform 0.2s ease, box-shadow 0.2s ease;
    }
    .card-solid:hover {
      transform: translateY(-2px);
      box-shadow: 0 8px 16px rgba(0,0,0,0.06);
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    }
    .faq-answer.active {
      max-height: 280px;
    }