body {
  font-family: Arial, sans-serif;
  text-align: center;
  margin: 0;
  padding: 0;
  background: #f0f0f0;
}

#controls {
  background: #4682b4;
  color: white;
  padding: 10px;
}

#controls label, #controls button, #controls input {
  margin: 0 5px;
}

#puzzleCanvas {
  display: block;
  margin: 20px auto;
  background: lightgray;
  border: 2px solid #333;
}