html, body {
width: 100%; height: 100%; padding: 0; margin: 0;
}
body {
  background-color: #ffffff; display: flex; justify-content: center; align-items: center;
}
canvas { 
max-width: 100%; max-height: 100%; margin: auto; overflow: auto; position: fixed; object-fit: contain; top: 0; bottom: 0; left: 0; right: 0;
}