body {
  font-family: system-ui, sans-serif;
  margin: 0;
  padding: 2rem;
  background: #f5f5f5;
}

main {
  max-width: 720px;
  margin: 0 auto;
  background: #fff;
  padding: 2rem;
  border-radius: 12px;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.08);
}

pre {
  background: #111;
  color: #0f0;
  padding: 1rem;
  border-radius: 8px;
  overflow-x: auto;
}

h1 {
  font-size: 1.8rem;
  margin-bottom: 1rem;
}