*, *:before, *:after {
  box-sizing: inherit;
}

html, body {
  height: 100%;
  box-sizing: border-box;
}

body {
  background-color: #000;
  margin: 0;
  padding: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-family: sans-serif;
}

main {
  text-align: left;
}

a {
  color: inherit;
}
a:hover, a:focus {color: #66F;}

code {
  display: inline-block;
  font-size: 1.2em;
  line-height: 1;
  padding: 0.5em 0.5em 0.2em;
  background-color: #222;
}

ul {
  list-style: none;
  padding-left: 0;
}

footer {
  position: fixed;
  bottom: 0;
  left: 0;
  max-width: 100vw;
  color: white;
  background-color: rgba(0, 0, 0, 0.8);
  padding: 0.5em 1em;
  border-top-right-radius: 0.5em;
}