body {
  max-width: 700px;
  margin: 0 auto;
  font-family: sans-serif;
  font-size: 1.1em;
  text-align: left;
  background-color: #222233;
  color: white;
}
a {
  color: beige;
}
a:visited {
  color: white;
}
h1 {
  text-align: center;
}
img {
  max-width: 100%;
}
.subtitle {
  text-align: center;
}
.callout {
  background-color: #224444;
  text-align: center;
}
.verbatim {
  font-family: monospace;
  font-size: 1.1em;
}