body {
  margin: 0;
  background: #102b3e;
  color: #192e40;
  font:
    16px/1.6 Arial,
    sans-serif;
}
main {
  max-width: 560px;
  margin: 8vh auto;
  padding: 40px;
  background: #fafbf9;
  border-radius: 16px;
}
h1 {
  line-height: 1.2;
}
button,
a {
  display: inline-block;
  margin: 8px 12px 0 0;
  padding: 10px 16px;
  border: 1px solid #174b68;
  border-radius: 6px;
  background: #174b68;
  color: white;
  font: inherit;
  text-decoration: none;
}
button:disabled {
  opacity: 0.5;
}
#message {
  white-space: pre-wrap;
}
@media (max-width: 640px) {
  main {
    margin: 20px;
    padding: 24px;
  }
}