body {
  font-family: sans-serif;
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 1rem;
  background: #f5f5f5;
}

h1 {
  margin-bottom: 1rem;
}

.controls {
  margin-bottom: 1rem;
}

canvas {
  border: 1px solid #ccc;
  background: white;
}
.controls label {
  margin-right: 1rem;
}

.controls input[type="text"] {
  width: 150px;
}