body {
  max-width: 40em;
  margin: 0 auto;
  padding: 0 1em;
}

nav {
  margin-bottom: 2em;
}

nav a {
  margin-right: 1.2em;
  text-decoration: none;
  color: #666;
}

nav a:hover {
  text-decoration: underline;
}

nav a.current {
  color: #000;
  font-weight: bold;
}