body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  line-height: 1.6;
  color: #333;
  max-width: 800px;
  margin: 0 auto;
  padding: 20px;
}

header {
  background-color: #f4f4f4;
  padding: 20px;
  margin-bottom: 20px;
}

header h1 {
  margin: 0;
}

nav {
  margin-top: 10px;
}

nav a {
  margin-right: 10px;
  text-decoration: none;
  color: #0366d6;
}

main {
  background-color: #fff;
  padding: 20px;
  border-radius: 5px;
  box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
}

h1,
h2,
h3 {
  color: #0366d6;
}

footer {
  margin-top: 20px;
  text-align: center;
  font-size: 0.9em;
  color: #777;
}

a {
  color: #0366d6;
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}