:root {
  --bg: #fbfaf7;
  --fg: #1d1d1f;
  --muted: #5f5f66;
  --line: #e4e2dc;
  --accent: #3b5bdb;
  color-scheme: light dark;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #141417;
    --fg: #ececef;
    --muted: #9c9ca6;
    --line: #2a2a30;
    --accent: #8ea4ff;
  }
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font: 17px/1.6 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}
main, header, footer { max-width: 42rem; margin: 0 auto; padding: 0 1rem; }
header { display: flex; align-items: center; justify-content: space-between; padding-top: 1.5rem; }
header a { color: var(--fg); text-decoration: none; font-weight: 600; }
.brand { display: inline-flex; align-items: center; gap: .5rem; }
nav a { color: var(--muted); font-weight: 400; margin-left: 1rem; }
h1 { font-size: 2.2rem; line-height: 1.2; margin: 3rem 0 .75rem; letter-spacing: -.02em; }
h2 { font-size: 1.2rem; margin: 2.25rem 0 .5rem; }
p, li { color: var(--fg); }
.lede { font-size: 1.2rem; color: var(--muted); margin-top: 0; }
a { color: var(--accent); }
kbd {
  font: .85em ui-monospace, SFMono-Regular, Menlo, monospace;
  border: 1px solid var(--line);
  border-bottom-width: 2px;
  border-radius: 4px;
  padding: .05em .35em;
}
.flip {
  display: grid;
  grid-template-columns: 1fr 1fr;
  border: 1px solid var(--line);
  border-radius: 12px;
  overflow: hidden;
  margin: 2rem 0;
}
.flip div { padding: 1.25rem; font-size: .95rem; }
.flip .l { background: #fff; color: #1d1d1f; }
.flip .d { background: #1d1d1f; color: #ececef; }
.flip b { display: block; margin-bottom: .25rem; }
ul { padding-left: 1.2rem; }
figure { margin: 1.5rem 0; }
figure img { display: block; width: 100%; height: auto; }
figcaption { color: var(--muted); font-size: .9rem; margin-top: .5rem; }
footer { color: var(--muted); font-size: .9rem; border-top: 1px solid var(--line); margin-top: 4rem; padding-top: 1rem; padding-bottom: 2rem; }
footer a { color: var(--muted); margin-right: 1rem; }
footer p { color: var(--muted); margin: .75rem 0 0; }
footer p a { margin-right: 0; }