:root {
  color-scheme: light dark;
  --bg: #fff;
  --fg: #111;
  --link: #065fd4;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #121212;
    --fg: #f5f5f5;
    --link: #4ea1f3;
  }
}

body {
  margin: 0;
  font-family: Tahoma, Verdana, sans-serif;
  background-color: var(--bg);
  color: var(--fg);
  padding: 2em;
  max-width: 720px;
  margin-left: auto;
  margin-right: auto;
  line-height: 1.6;
}

h1 {
  font-size: 2em;
  border-bottom: 2px solid var(--fg);
  padding-bottom: 0.3em;
}

a {
  color: var(--link);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

.section {
  margin-top: 2em;
}