body {
  font-family: 'Helvetica Neue', Arial, sans-serif;
  margin: 0;
  padding: 0;
  background: #f9f9f9;
  color: #222;
}
header {
  background: #222;
  color: #fff;
  padding: 2rem 1rem 1rem 1rem;
  text-align: center;
}
nav a {
  color: #fff;
  margin: 0 1em;
  text-decoration: none;
  font-weight: bold;
}
nav a:hover {
  text-decoration: underline;
}
main {
  max-width: 700px;
  margin: 2rem auto;
  background: #fff;
  padding: 2rem;
  border-radius: 8px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.05);
}
footer {
  text-align: center;
  padding: 1rem;
  color: #888;
  font-size: 0.9em;
}