html {
  width: 100%;
  height: 100%;
}
body {
  padding-top: 2em;
  padding-bottom: 2em;
  font-family: 'Roboto Mono';
  font-size: 3.75em;
  font-weight: 700;
  letter-spacing: 1em;
  color: #252525;
  background-color: #000;
}
.on {
  color: #fff;
  text-shadow: 0 0 0.35em #bbb;
}