body {
  margin: 0;
  height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  background: #111;
  color: #eee;
  font-family: Arial, Helvetica, sans-serif;
}

#landing {
  text-align: center;
}

.selector {
  margin-top: 2rem;
}

select {
  padding: 0.5rem 1rem;
  font-size: 1rem;
  border-radius: 4px;
  border: none;
  background: #222;
  color: #fff;
}

button {
  padding: 0.5rem 1rem;
  font-size: 1rem;
  border: none;
  border-radius: 4px;
  margin-left: 1rem;
  cursor: pointer;
  background: #0f8;
  color: #000;
}

.hidden {
  display: none;
}