html,body {
  margin: 0;
  position: relative;
  min-height: 100vh;
}
canvas {
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
  max-width: 100%;
  max-height: 100%;
  object-fit: scale-down;
  filter: drop-shadow(0.3rem 0.3rem 0.3rem rgba(0,0,0,0.43));
}