body {
  font-family: sans-serif;
  margin: 0;
  padding: 0;
  line-height: 1.6;
}
header {
  background: #333;
  color: white;
  padding: 1em 0;
  text-align: center;
}
nav a {
  margin: 0 1em;
  color: #ccc;
  text-decoration: none;
}
nav a:hover {
  color: white;
}
main {
  padding: 2em;
}
footer {
  background: #f4f4f4;
  text-align: center;
  padding: 1em;
}