body {
  max-width: 40em;
  margin: auto;
  padding: 5px;
  font-family: verdana, arial;
  font-size: 18px;
  line-height: 1.6em;
  color: black;
  background-color: silver;
  text-align: center;
}
h1, h2, h3 {
  font-family: sans-serif;
  font-weight: normal;
  margin: auto;
  text-align: center;
}
p{
  font-family: "times", "courier new";
  font-size: 1em;
  font-weight: normal;
  text-align: center;
}
pre{
  font-family: "times", "courier new";
  margin: auto;
  font-size: 1em;
  font-weight: normal;
  text-align: center;
}
.box{
  border: 2px solid;
  height: auto;
  width: auto;
}