@media (prefers-color-scheme: dark) {
  body {
    background: #000000;
  }
  body header, body header nav ul li, body section, body footer {
    background: #000022;
    color: #ffff88;
  }
  a:link, a:visited {
    background: #000022;
    color: #ffff88;
    text-decoration: none;
  }
  body section nav ol li, body section nav ul li {
    border: 1px solid yellow;
  }
}