body {
  margin: 3em;
  margin-top: 1em;
}

h1 {
  background: lightblue;
}

h3 {
  color: white;
  background: green;
}



a:hover {
  background: lightgrey;
}

A {
 color: blue;
 text-decoration: underline;
}

A:visited { color: #330099; }