body {
  max-width: 45rem;
  margin: auto;
  padding: 0.5em;
  text-align: justify;
  font-family: "Times New Roman", serif;
}
h1, h2, h3, h4 {
  font-family: arial, sans;
}
h1 {
  text-align: center;
}
pre {
  padding: 1ch;
  background-color: #f5f5f5;
  overflow: auto;
}
img {
  	display: block;
	margin: auto;
	max-width: 100%;
}
footer {
  text-align: center;
  font-size: 0.8em;
}