body {
  font-family: monospace;
  font-size: large;
  display: flex;
  flex-direction: column;
  align-items: center;
}

.error {
  color: red;
  font-weight: bold;
  padding: 1em 0;
}

.waiting {
  padding: 1.5em 0;
  font-size: x-large;
}

.message {
  color: green;
  font-weight: bold;
  padding: 1em 0;
}

.btn {
  font-family: monospace;
  border-radius: 0.5em;
  font-size: xx-large;
  padding: 0.5em 0;
  margin: 0.5em;
  color: green;
  width: 5em;
}

.btn-success {
  background: green;
  color: white;
}

.btn-danger {
  background: red;
  color: white;
}