body {
  font-family: Arial, sans-serif;
  margin: 0;
  padding: 0;
  background: #f8f8f8;
  color: #333;
}
header, nav, footer {
  background: #003366;
  color: white;
  padding: 1em;
  text-align: center;
}
nav ul {
  list-style: none;
  padding: 0;
}
nav ul li {
  display: inline;
  margin: 0 15px;
}
nav ul li a {
  color: white;
  text-decoration: none;
}
main {
  padding: 20px;
}
section {
  margin-bottom: 30px;
}
footer {
  margin-top: 40px;
}