body {
font-family: Arial, sans-serif;
margin: 20px;
background: #f5f5f5;
color: #333;
}

h1 {
text-align: center;
}
.controls {
text-align: center;
margin-bottom: 10px;
}
canvas {
display: block;
margin: 0 auto;
border: 1px solid #999;
background: #fff;
cursor: crosshair;
}