body {
  margin: 0;
  background: linear-gradient(#6dd5fa, #ffffff);
  font-family: 'Arial', sans-serif;
  text-align: center;
}

#ui {
  padding: 10px;
}

canvas {
  border: 4px solid #333;
  background: linear-gradient(#87ceeb, #dff6ff);
  border-radius: 12px;
}