html,
body,
main {
  height: 100%;
  width: 100%;
  margin: 0;
  background-color: #111;
}
main {
  display: flex;
  align-items: center;
  justify-content: center;
}
canvas {
  height: auto !important;
  width: auto !important;
  max-width: 100% !important;
  max-height: 100% !important;
}