/* roulang page: index */
:root {
      --color-primary: #0F172A;
      --color-brand: #0284C7;
      --color-accent: #0D9488;
      --color-bg-light: #F8FAFC;
    }
    body {
      font-family: system-ui, -apple-system, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
      line-height: 1.75;
      background-color: var(--color-bg-light);
      color: #334155;
    }
    .grid-bg-overlay {
      background-image: linear-gradient(to right, rgba(255, 255, 255, 0.05) 1px, transparent 1px),
                        linear-gradient(to bottom, rgba(255, 255, 255, 0.05) 1px, transparent 1px);
      background-size: 32px 32px;
    }
    .tab-content { display: none; }
    .tab-content.active { display: block; }