/* roulang page: index */
:root {
      --primary-color: #1A365D;
      --accent-color: #D97706;
      --dark-color: #0F172A;
      --deep-color: #0B192C;
      --surface-color: #F8FAFC;
      --border-color: #E2E8F0;
    }
    body {
      font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "WenQuanYi Micro Hei", sans-serif;
      line-height: 1.8;
      color: #0F172A;
      background-color: #FFFFFF;
      text-rendering: optimizeLegibility;
      -webkit-font-smoothing: antialiased;
    }
    h1, h2, h3, h4, h5, h6 {
      line-height: 1.35;
      font-weight: 700;
      color: #0F172A;
    }
    .shadow-hover {
      transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    }
    .shadow-hover:hover {
      transform: translateY(-4px);
      box-shadow: 0 12px 24px -6px rgba(15, 23, 42, 0.12), 0 8px 16px -8px rgba(15, 23, 42, 0.08);
    }
    .faq-answer {
      transition: max-height 0.35s ease-out, opacity 0.3s ease-out;
      max-height: 0;
      overflow: hidden;
      opacity: 0;
    }
    .faq-answer.open {
      max-height: 480px;
      opacity: 1;
    }
    .rotate-icon {
      transition: transform 0.3s ease;
    }
    .rotate-icon.rotated {
      transform: rotate(180deg);
    }