body {
  font-family: system-ui, sans-serif;
  line-height: 1.6;
  margin: 0;
  padding: 0;
  color: #222;
}

header, main, footer {
  max-width: 900px;
  margin: auto;
  padding: 1.5rem;
}

nav a {
  margin-right: 1rem;
  text-decoration: none;
}

nav a:hover {
  text-decoration: underline;
}