body {
  margin: 20px;
  background-color: white;
  padding: 20px;
  border: thin ridge rgb(0, 0, 200);
}

h1 {
  text-align: center;
}

pre {
  border: thin solid rgb(200,200,200);
  background-color: rgb(230,230,230);
  margin-left: 40px;
}