body {
  margin: 0;
  font-family: Arial, sans-serif;
  line-height: 1.6;
  background: #f4f4f9;
  color: #333;
}
header {
  background: #003366;
  color: #fff;
  padding: 20px 0;
  text-align: center;
}
nav ul {
  list-style: none;
  padding: 0;
}
nav ul li {
  display: inline;
  margin: 0 15px;
}
nav ul li a {
  color: #fff;
  text-decoration: none;
  font-weight: bold;
}
nav ul li a:hover {
  text-decoration: underline;
}
.container {
  width: 80%;
  margin: auto;
  overflow: hidden;
  padding: 20px 0;
}
h1, h2, h3 {
  color: #003366;
}
footer {
  text-align: center;
  padding: 15px;
  background: #003366;
  color: #fff;
  margin-top: 20px;
}