body {
  max-width: 640px;
  margin: 0 0 0 auto;
  padding: 8px;
  font-family: sans-serif;
}

ul {
  padding-inline-start: 30px;
  list-style-type: none;
}

p {
  padding: 30px;
}

img {
  margin: 10px auto;
  max-width: 100%;
}

p a, footer a {
  float: right
}

hr {
  clear: both
}

footer a {
  padding-bottom: 10px;
}

@media (prefers-color-scheme: dark) {
  body { background: #000; color: #eee }
  a { color: #ccf }
  hr { border-color: #555 }
}