body {
  text-align: center;
  font-family: Arial;
  background: #157f3f;
  color: white;
}

canvas {
  background: #2ecc71;
  border: 4px solid white;
  margin-top: 20px;
}

button {
  padding: 8px 16px;
  font-size: 16px;
  margin-top: 10px;
}