:root {
    --text: #1d1d1f;
    --text-secondary: #6e6e73;
    --text-tertiary: #86868b;
    --link: #0066cc;
    --rule: #d2d2d7;
    --band: #f5f5f7;
  }
  * { margin: 0; padding: 0; box-sizing: border-box; }
  html { -webkit-text-size-adjust: 100%; }
  body {
    font-family: -apple-system, BlinkMacSystemFont, "SF Pro SC", "SF Pro Text", "PingFang SC", "Helvetica Neue", "Segoe UI", Arial, sans-serif;
    color: var(--text);
    background: #fff;
    line-height: 1.7;
    font-size: 15px;
    -webkit-font-smoothing: antialiased;
    text-rendering: optimizeLegibility;
  }
  a { color: var(--link); text-decoration: none; }
  a:hover { text-decoration: underline; }

  .page-header {
    background: var(--band);
    border-bottom: 1px solid var(--rule);
    padding: 14px 22px;
  }
  .page-header .inner {
    max-width: 720px; margin: 0 auto;
    display: flex; align-items: baseline; justify-content: space-between; gap: 16px;
  }
  .page-header .brand { font-size: 16px; font-weight: 600; letter-spacing: -.01em; }
  .page-header .lang { font-size: 13px; color: var(--text-secondary); white-space: nowrap; }
  .page-header .lang a { margin-left: 12px; }
  .page-header .lang .current { color: var(--text); font-weight: 600; }

  main { max-width: 720px; margin: 0 auto; padding: 34px 22px 20px; }

  h1 { font-size: 30px; font-weight: 700; letter-spacing: -.015em; line-height: 1.2; }
  .scope { margin-top: 10px; font-size: 13.5px; color: var(--text-secondary); }
  .updated { margin-top: 4px; font-size: 13px; color: var(--text-tertiary); }

  section { margin-top: 26px; }
  h2 { font-size: 19px; font-weight: 700; letter-spacing: -.01em; margin-bottom: 7px; }
  p { margin: 7px 0; color: var(--text); }
  p.secondary { color: var(--text-secondary); }
  ul { margin: 7px 0 7px 20px; }
  li { margin: 4px 0; }
  li::marker { color: var(--text-tertiary); }
  strong { font-weight: 600; }

  .rule { border: 0; border-top: 1px solid var(--rule); margin: 30px 0 0; }

  footer {
    border-top: 1px solid var(--rule);
    margin-top: 40px;
    padding: 18px 22px 34px;
    font-size: 12px;
    color: var(--text-tertiary);
  }
  footer .inner { max-width: 720px; margin: 0 auto; }
  footer p { margin: 3px 0; color: var(--text-tertiary); font-size: 12px; line-height: 1.6; }

  @media (max-width: 600px) {
    h1 { font-size: 26px; }
    body { font-size: 14.5px; }
    .page-header .lang { font-size: 12.5px; }
  }