:root {
  color-scheme: light dark;
  --bg: #ffffff;
  --fg: #1a1a1a;
  --muted: #5a5a5a;
  --border: #d0d0d0;
  --link: #0056b3;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #121212;
    --fg: #e8e8e8;
    --muted: #a0a0a0;
    --border: #3a3a3a;
    --link: #6cb2ff;
  }
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  padding: 0 1rem;
  background: var(--bg);
  color: var(--fg);
  font-family:
    -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial,
    sans-serif;
  line-height: 1.5;
}

header,
main,
footer {
  max-width: 70ch;
  margin: 0 auto;
}

header {
  padding: 1.5rem 0;
}

header a {
  font-weight: bold;
  font-size: 1.1rem;
  text-decoration: none;
}

main {
  padding: 1rem 0 2rem;
}

footer {
  padding: 1.5rem 0 2rem;
  border-top: 1px solid var(--border);
  font-size: 0.9rem;
  color: var(--muted);
}

h1 {
  font-size: 1.8rem;
  margin: 0 0 1rem;
}

h2 {
  font-size: 1.3rem;
  margin: 2rem 0 0.75rem;
}

p {
  margin: 0 0 1rem;
}

ul {
  margin: 0 0 1rem;
  padding-left: 1.5rem;
}

li {
  margin: 0 0 0.5rem;
}

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

a:hover,
a:focus {
  text-decoration: none;
}

.card {
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 1rem 1.25rem;
  margin: 0 0 1rem;
}

.muted {
  color: var(--muted);
  font-size: 0.9rem;
}