body {
  background: #f9f9f9;
  font-family: sans-serif;
  margin: 0;
  padding: 0;
}

header, footer {
  background: #eee;
  padding: 1em;
  text-align: center;
}

main {
  max-width: 700px;
  margin: 2em auto;
  background: white;
  padding: 2em;
  border-radius: 8px;
  box-shadow: 0 1px 6px rgba(0,0,0,0.1);
}

nav a {
  margin: 0 1em;
  color: #333;
  text-decoration: none;
}