:root {
  --bg: #ffffff;
  --fg: #1b1b1b;
  --muted: #5a5a5a;
  --line: #d9d9d9;
  --code-bg: #f3f3f3;
  --link: #0b57a8;
  --accent: #b35900;
  color-scheme: light dark;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #141414;
    --fg: #e6e6e6;
    --muted: #a3a3a3;
    --line: #333333;
    --code-bg: #1f1f1f;
    --link: #7fb6ff;
    --accent: #f0a050;
  }
}

* { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  font-size: 17px;
  line-height: 1.55;
}

header, main, footer {
  max-width: 52rem;
  margin: 0 auto;
  padding: 0 1rem;
}

header {
  padding-top: 1.5rem;
  border-bottom: 1px solid var(--line);
}

header .brand {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--fg);
  text-decoration: none;
}

nav {
  display: flex;
  flex-wrap: wrap;
  gap: 0.25rem 1rem;
  padding: 0.5rem 0 0.75rem;
  font-size: 0.95rem;
}

main { padding-top: 1rem; padding-bottom: 2rem; }

footer {
  border-top: 1px solid var(--line);
  padding-top: 1rem;
  padding-bottom: 2rem;
  color: var(--muted);
  font-size: 0.9rem;
}

footer nav { padding: 0 0 0.5rem; }

h1 { font-size: 1.8rem; line-height: 1.25; margin: 1rem 0 0.5rem; }
h2 { font-size: 1.35rem; margin: 2rem 0 0.5rem; border-bottom: 1px solid var(--line); padding-bottom: 0.2rem; }
h3 { font-size: 1.1rem; margin: 1.5rem 0 0.4rem; }

a { color: var(--link); }

.lead { font-size: 1.1rem; }
.muted { color: var(--muted); }

.todo {
  border-left: 4px solid var(--accent);
  padding: 0.4rem 0.75rem;
  background: var(--code-bg);
  font-size: 0.95rem;
}

code, pre, kbd {
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, "Liberation Mono", monospace;
  font-size: 0.88em;
}

code {
  background: var(--code-bg);
  padding: 0.05rem 0.3rem;
  border-radius: 3px;
  overflow-wrap: anywhere;
}

pre {
  background: var(--code-bg);
  border: 1px solid var(--line);
  border-radius: 4px;
  padding: 0.75rem;
  overflow-x: auto;
  line-height: 1.4;
}

pre code { background: none; padding: 0; overflow-wrap: normal; }

.table-wrap { overflow-x: auto; }

table {
  border-collapse: collapse;
  width: 100%;
  margin: 0.5rem 0 1rem;
  font-size: 0.95rem;
}

th, td {
  border: 1px solid var(--line);
  padding: 0.35rem 0.55rem;
  text-align: left;
  vertical-align: top;
}

th { background: var(--code-bg); }

td.num, th.num { text-align: right; white-space: nowrap; }

ul, ol { padding-left: 1.4rem; }
li { margin: 0.2rem 0; }