body {
  text-align: center;
  font-family: Arial, sans-serif;
  background: #f4f4f4;
  padding: 20px;
}
canvas {
  border: 1px solid #ccc;
  max-width: 100%;
  margin-top: 20px;
}
input, select, button {
  margin: 10px;
  padding: 10px;
}