/* One reading column; the contents run beside it on a wide screen and
     above it on a narrow one. Accent is 2Notch's own orange. */
  :root {
    --bg: #fbfaf8; --fg: #1c1b19; --muted: #6b665f; --line: #e7e3dd;
    --accent: #d86a00; --mark: #111110;
    --display: "Bricolage Grotesque", ui-sans-serif, system-ui, sans-serif;
    --body: "Source Sans 3", -apple-system, BlinkMacSystemFont, "Helvetica Neue", sans-serif;
    --mono: "JetBrains Mono", ui-monospace, "SF Mono", Menlo, monospace;
  }
  @media (prefers-color-scheme: dark) {
    :root:not([data-theme="light"]) {
      --bg: #131211; --fg: #efece7; --muted: #a39d94; --line: #2b2926;
      --accent: #ff9a3d; --mark: #000000; color-scheme: dark;
    }
  }
  :root[data-theme="dark"] {
    --bg: #131211; --fg: #efece7; --muted: #a39d94; --line: #2b2926;
    --accent: #ff9a3d; --mark: #000000; color-scheme: dark;
  }
  body { margin: 0; background: var(--bg); color: var(--fg);
         font: 17px/1.62 var(--body); padding-inline: 20px; }
  .page { max-width: 1060px; margin: 0 auto; padding-block: 56px 88px;
          display: grid; grid-template-columns: 220px minmax(0, 1fr); gap: 56px; }
  header { grid-column: 1 / -1; display: flex; flex-direction: column; gap: 14px; }
  .mark { width: 54px; height: 38px; border-radius: 10px; background: var(--mark);
          position: relative; }
  .mark::after { content: ""; position: absolute; left: 50%; top: 0; width: 26px; height: 12px;
                 transform: translateX(-50%); background: var(--accent);
                 border-radius: 0 0 7px 7px; }
  h1 { font: 700 clamp(28px, 4.2vw, 40px)/1.12 var(--display); margin: 0;
       letter-spacing: -0.01em; text-wrap: balance; }
  .updated { font: 13px/1.4 var(--mono); color: var(--muted); margin: 0; }
  nav { position: sticky; top: calc(env(safe-area-inset-top, 0px) + 24px);
        align-self: start; font-size: 14px; line-height: 1.35; }
  nav h2 { font: 600 11px/1 var(--body); letter-spacing: 0.08em; text-transform: uppercase;
           color: var(--muted); margin: 0 0 12px; }
  nav ol { list-style: none; margin: 0; padding: 0; display: grid; gap: 7px;
           counter-reset: toc; }
  nav li { counter-increment: toc; display: grid; grid-template-columns: 2.1em 1fr; }
  nav li::before { content: counter(toc); font: 12px/1.6 var(--mono); color: var(--muted);
                   font-variant-numeric: tabular-nums; }
  nav a { color: var(--fg); text-decoration: none; }
  nav a:hover { color: var(--accent); }
  main { min-width: 0; max-width: 68ch; }
  section { padding-block: 22px; border-top: 1px solid var(--line); scroll-margin-top: 16px; }
  section:first-child { border-top: 0; padding-top: 0; }
  main h2 { font: 650 20px/1.3 var(--display); margin: 0 0 10px; text-wrap: balance; }
  p { margin: 0 0 12px; }
  ul { margin: 0 0 12px; padding-left: 22px; display: grid; gap: 4px; }
  ul.checks { list-style: none; padding-left: 0; gap: 8px; }
  ul.checks li { display: grid; grid-template-columns: 1.6em 1fr; }
  ul.checks li::before { content: "✓"; color: var(--accent); font-weight: 700; }
  a { color: var(--accent); }
  a:focus-visible, button:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
  .contact { margin-top: 28px; padding: 18px 20px; border: 1px solid var(--line);
             border-radius: 12px; display: flex; flex-wrap: wrap; align-items: center; gap: 10px 16px; }
  .contact code { font: 15px/1.4 var(--mono); user-select: all; overflow-wrap: anywhere; }
  .contact button { font: 600 13px/1 var(--body); color: var(--fg); background: transparent;
                    border: 1px solid var(--line); border-radius: 999px; padding: 8px 14px; cursor: pointer; }
  .contact button:hover { border-color: var(--accent); color: var(--accent); }
  @media (max-width: 820px) {
    .page { grid-template-columns: minmax(0, 1fr); gap: 32px; padding-block: 32px 64px; }
    nav { position: static; }
    nav ol { grid-template-columns: repeat(auto-fill, minmax(190px, 1fr)); }
  }
  @media (prefers-reduced-motion: no-preference) { html { scroll-behavior: smooth; } }