body {
  font-family: sans-serif;
  background-color: #111;
  color: #0f0;
  text-align: center;
  padding: 2em;
}
button {
  background: #0f0;
  color: #000;
  padding: 1em;
  font-size: 1.2em;
  border: none;
  border-radius: 8px;
}