body {
  margin: 0;
  height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  background: #111;
  color: #fff;
  font-family: monospace;
  text-align: center;
}
h1 {
  font-size: 2rem;
}
h3 {
  color: #888;
}