:root {
  color-scheme: light dark;
  --ink: #1a1a1a;
  --paper: #fdfdfc;
  --faint: #666;
  --rule: #ddd;
  --shade: #f4f4f2;
  --link: #0b5;
}
@media (prefers-color-scheme: dark) {
  :root {
    --ink: #e8e8e6;
    --paper: #16161a;
    --faint: #999;
    --rule: #333;
    --shade: #1e1e24;
    --link: #4d9;
  }
}
* { box-sizing: border-box; }
body {
  margin: 0 auto;
  padding: 2.5rem 1.5rem 5rem;
  max-width: 64rem;
  display: grid;
  grid-template-columns: 12rem minmax(0, 1fr);
  gap: 0 4rem;
  background: var(--paper);
  color: var(--ink);
  font: 16px/1.6 ui-serif, Georgia, "Times New Roman", serif;
}
main { min-width: 0; max-width: 44rem; }
footer { grid-column: 2; }
h1, h2, h3 { font-family: ui-sans-serif, system-ui, sans-serif; line-height: 1.25; }
h1 { font-size: 1.9rem; margin: 0 0 1.5rem; }
h2 { font-size: 1.3rem; margin: 2.5rem 0 0.75rem; }
h3 { font-size: 1.05rem; margin: 2rem 0 0.5rem; }
a { color: var(--link); }
code, pre {
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  font-size: 0.875em;
}
code { background: var(--shade); padding: 0.1em 0.3em; border-radius: 3px; }
pre {
  background: var(--shade);
  padding: 0.9rem 1rem;
  border-radius: 4px;
  overflow-x: auto;
  line-height: 1.45;
}
pre code { background: none; padding: 0; }
table { border-collapse: collapse; width: 100%; margin: 1rem 0; }
th, td { text-align: left; padding: 0.4rem 0.6rem; border-bottom: 1px solid var(--rule); }
blockquote { margin: 1rem 0; padding-left: 1rem; border-left: 3px solid var(--rule); color: var(--faint); }
hr { border: 0; border-top: 1px solid var(--rule); margin: 2.5rem 0; }
nav {
  position: sticky;
  top: 2.5rem;
  align-self: start;
  font-family: ui-sans-serif, system-ui, sans-serif;
  font-size: 0.85rem;
  line-height: 1.5;
}
nav .home {
  display: block;
  margin-bottom: 1.5rem;
  color: var(--ink);
  font-size: 1.05rem;
  font-weight: 600;
  text-decoration: none;
}
nav h2 {
  margin: 1.5rem 0 0.4rem;
  font-size: 0.7rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--faint);
}
nav ul { margin: 0; padding: 0; list-style: none; }
nav li { margin: 0.15rem 0; }
nav a { color: var(--faint); text-decoration: none; }
nav a:hover { color: var(--link); }
nav [aria-current="page"] {
  color: var(--ink);
  font-weight: 600;
  border-left: 2px solid var(--link);
  margin-left: -0.6rem;
  padding-left: 0.4rem;
}

/* Narrow enough that a column beside the text would leave no text: the
   navigation goes above it, as a plain list. */
@media (max-width: 52rem) {
  body { display: block; padding: 1.5rem 1.25rem 4rem; }
  nav {
    position: static;
    margin-bottom: 2.5rem;
    padding-bottom: 1rem;
    border-bottom: 1px solid var(--rule);
  }
  nav h2 { margin-top: 1rem; }
  nav ul { display: flex; flex-wrap: wrap; gap: 0.2rem 1rem; }
  nav [aria-current="page"] { border: 0; margin-left: 0; padding-left: 0; }
}
footer {
  margin-top: 4rem;
  padding-top: 1rem;
  border-top: 1px solid var(--rule);
  font-family: ui-sans-serif, system-ui, sans-serif;
  font-size: 0.8rem;
  color: var(--faint);
}
footer a { color: var(--faint); }