body {
  text-align: center;
  font-family: Arial, sans-serif;
  background: #000;
  color: #fff;
}

h1 {
  margin-top: 20px;
}

canvas {
  border: 2px solid #fff;
  background: #111;
  margin-top: 20px;
}

.controls {
  margin-top: 15px;
}

label {
  margin: 0 10px;
  color: #fff;
}

input {
  width: 60px;
}

#message {
  font-size: 1.2em;
  margin-top: 15px;
  color: lime;
}