:root {
    --bg: #ffffff;
    --surface: #f5f5f7;
    --text: #1d1d1f;
    --muted: #6e6e73;
    --border: #d2d2d7;
    --accent: #0071e3;
    --maxw: 720px;
  }
  @media (prefers-color-scheme: dark) {
    :root {
      --bg: #000000;
      --surface: #1c1c1e;
      --text: #f5f5f7;
      --muted: #a1a1a6;
      --border: #38383a;
      --accent: #2997ff;
    }
  }
  * { box-sizing: border-box; }
  html { -webkit-text-size-adjust: 100%; color-scheme: light dark; }
  body {
    margin: 0;
    background: var(--bg);
    color: var(--text);
    font: 17px/1.6 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    padding: 0 20px;
  }
  main { max-width: var(--maxw); margin: 0 auto; padding: 56px 0 96px; }
  header { text-align: center; margin-bottom: 48px; }
  h1 { font-size: 34px; line-height: 1.15; letter-spacing: -0.02em; margin: 0 0 8px; }
  .tagline { color: var(--muted); font-size: 19px; margin: 0; }
  h2 {
    font-size: 24px; letter-spacing: -0.01em; margin: 48px 0 12px;
    padding-top: 24px; border-top: 1px solid var(--border);
  }
  h3 { font-size: 19px; margin: 28px 0 6px; }
  p, li { color: var(--text); }
  .muted { color: var(--muted); }
  a { color: var(--accent); text-underline-offset: 3px; }
  a:hover { text-decoration-thickness: 2px; }
  .updated { color: var(--muted); font-size: 15px; }
  .callout {
    background: var(--surface); border: 1px solid var(--border);
    border-radius: 14px; padding: 18px 20px; margin: 20px 0;
  }
  .callout strong { display: block; margin-bottom: 4px; }
  .callout h2 { border: 0; padding: 0; margin: 0 0 12px; font-size: 21px; }
  .callout p:last-child { margin-bottom: 0; }
  ul { padding-left: 22px; }
  li { margin: 6px 0; }
  footer {
    margin-top: 64px; padding-top: 24px; border-top: 1px solid var(--border);
    color: var(--muted); font-size: 14px; text-align: center;
  }
  code {
    font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
    background: var(--surface); padding: 1px 6px; border-radius: 6px; font-size: 15px;
  }

  .site-nav { display: flex; flex-wrap: wrap; justify-content: center; gap: 8px 24px; margin-bottom: 40px; }
  .site-nav a { padding: 8px 0; text-decoration: none; }
  .site-nav [aria-current="page"] { color: var(--text); font-weight: 600; }
  .skip-link { position: absolute; left: 20px; top: -80px; }
  .skip-link:focus { top: 12px; }
  a:focus-visible { outline: 3px solid var(--accent); outline-offset: 4px; }
  .intro { max-width: 540px; margin: 20px auto; color: var(--muted); }
  .eyebrow { color: var(--muted); font-size: 15px; margin-bottom: 12px; }
  .platforms { color: var(--muted); font-size: 14px; margin-top: 24px; }
  .actions { display: flex; flex-wrap: wrap; justify-content: center; gap: 12px; margin-top: 28px; }
  .button { display: inline-block; border-radius: 10px; padding: 12px 18px; background: var(--text); color: var(--bg); text-decoration: none; font-weight: 600; }
  .button-secondary { background: var(--surface); color: var(--text); border: 1px solid var(--border); }
  .button:hover { text-decoration: underline; }
  .steps { padding-left: 24px; }
  .steps li { padding-left: 6px; margin: 18px 0; }
  aside.callout { margin-top: 48px; }
  details { border-bottom: 1px solid var(--border); }
  summary { padding: 18px 0; cursor: pointer; font-weight: 600; }
  summary:focus-visible { outline: 3px solid var(--accent); outline-offset: 4px; }
  details p { margin: 0 0 18px; }
  [id] { scroll-margin-top: 24px; }
  @media (max-width: 480px) {
    main { padding-top: 36px; }
    h1 { font-size: 30px; }
  }