body {
  font-family: Arial, sans-serif;
  background-color: #f4f4f4;
  margin: 0;
  padding: 0;
}

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

nav ul {
  list-style: none;
  display: flex;
  justify-content: center;
  padding: 0;
}

nav ul li {
  margin: 0 1em;
}

nav ul li a {
  text-decoration: none;
  color: #333;
  font-weight: bold;
}

main {
  padding: 2em;
  text-align: center;
}