body {
  font-family: Arial, sans-serif;
  margin: 20px;
  line-height: 1.5;
  color: #243345;
}
h1 { color: #0a4a8a; }
h2 { color: #1c2e44; margin-top: 1.2em; }
nav a { margin-right: 10px; text-decoration: none; color: #0a4a8a; }
ul { margin-left: 20px; }
button {
  background: #0a4a8a;
  color: #fff;
  border: none;
  padding: 8px 14px;
  border-radius: 6px;
  cursor: pointer;
}