body {
  background: ivory;
  margin: 40px 30px;
}

H1, H2, H3, H4 {
  color: maroon;
}
a:link {
  color: maroon;
}

a:visited {
  color: #00008B;
}

.listing {
  font-family: monospace;
  white-space: pre;
  background-color: khaki;
  padding: 5px 10px;
}

.command {
  font-family: monospace;
  white-space: pre;
  background-color: lightgrey;
  padding: 3px 10px;
}