body {
  font-family: sans-serif;
  margin: 2rem;
  background: #f2f2f2;
}
textarea {
  width: 100%;
  font-family: monospace;
}
pre {
  background: #111;
  color: lime;
  padding: 1rem;
  white-space: pre-wrap;
}
button {
  margin-top: 1rem;
  margin-right: 0.5rem;
}