footer {
  position: absolute;
  bottom: 0;
  line-height: 0;
  width: 100%;
}
.copyright {
  text-align: center;
  margin: 0 auto;
  color: white;
  font-family: monospace;
}
.copyright p a {
  color: white;
}
@media all and (max-width: 420px) {
  .copyright {
    line-height: 1.22rem;
    text-align: center;
    margin-left: 1em;
    font-size: 0.9em;
  }
  .copyright p a:first-child::after {
    content: "\A";
    white-space: pre;
    background-color: yellow;
  }
}