body {
  font-family: Arial, sans-serif;
  max-width: 850px;
  margin: 0 auto;
  padding: 20px;
  line-height: 1.6;
  color: #333;
  background-color: #f9f9f9;
}
header {
  text-align: center;
  border-bottom: 2px solid #ddd;
  margin-bottom: 20px;
  padding-bottom: 10px;
}
h1 {
  color: #0073e6;
}
nav a {
  margin: 0 10px;
  color: #0073e6;
  text-decoration: none;
}
nav a:hover {
  text-decoration: underline;
}
footer {
    text-align: center;
    border-top: 2px solid #ddd;
    margin-top: 30px;
    padding-top: 10px;
    font-size: 0.9em;
    color: #777;
}