body {
  margin: 2em;
  line-height: 1.4em;
  font-family: -apple-system, BlinkMacSystemFont, sans-serif;
  font-size: 18px;
  max-width: 1200px;
}

hr {
  margin: 1em 0;
  border: 1px solid #ccc;
}

img {
  display: block;
  width: 100%;
  max-width: 500px;
}

ul {
  padding-left: 1em;
}

a {
  color: blue;
}