body {
  font-family: system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial,
    sans-serif;
  max-width: 800px;
  margin: 40px auto;
  padding: 0 20px;
  line-height: 1.6;
  color: #333;
}
h1,
h2 {
  color: #111;
}
a {
  color: #0077cc;
  text-decoration: none;
}
a:hover {
  text-decoration: underline;
}
hr {
  border: 0;
  border-top: 1px solid #ddd;
  margin: 2rem 0;
}