body {
  font-family: system-ui, sans-serif;
  padding: 2rem;
  background: #f5f7fa;
}

h1 {
  margin-bottom: 1rem;
}

.nav li {
  margin: 0.5rem 0;
}

button {
  margin-right: 1rem;
  padding: 0.5rem 1rem;
  cursor: pointer;
}

pre {
  background: #111;
  color: #0f0;
  padding: 1rem;
  margin-top: 1rem;
}