body {
  width: 48em;
  margin: auto;
  font-family: sans-serif;
  font-size: 110%;
  line-height: 1.3;
}

h1 {
  font-size: 2em;
}

body > article {
  margin: 2em 0;
  border-top: 1pt solid #ccc;
}

article h1 {
  font-size: 1.5em;
}

article h2 {
  font-size: 1.3em;
}

article h3 {
  font-size: 1.1em;
}

article h4 {
  font-size: 1.0em;
}

blockquote {
  margin-left: 0.5em;
  border-left: 2pt solid #ccc;
  padding-left: 0.5em;
}

pre, code {
  border: 1px solid #ccc;
  background-color: #fafafa;
  padding: 0.1em 0.1em 0;
}

pre {
  padding: 0.3em 0.3em 0.1em;
}