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

header, footer {
  background-color: #333;
  color: white;
  text-align: center;
  padding: 1em;
}

nav {
  background-color: #555;
  text-align: center;
}

nav a {
  display: inline-block;
  padding: 1em;
  color: white;
  text-decoration: none;
}

nav a:hover {
  background-color: #777;
}

section {
  padding: 2em;
  max-width: 800px;
  margin: auto;
  background: white;
  margin-top: 1em;
  border-radius: 10px;
  box-shadow: 0 0 10px rgba(0,0,0,0.1);
}

h2 {
  color: #333;
}