main, footer {
  max-width: 40em;
  width: calc(100% - 2em);
}

main {
  margin-left: auto;
  padding-right: 3em;
}
main ul li {
  border: 1px solid black;
  border-radius: 0.2em;
  margin-bottom: 0.5em;
  width: 2em;
}
main ul li > * {
  display: block;
  padding: 0em 0.5em 0em 0.5em;
  top: 0;
  left: 0;
}