html,body {
  margin: 0;
  padding: 0;
  overflow: hidden;
  width: 100%;
  height: 100%;
}

canvas {
  margin: auto;
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: auto !important;
  width: auto !important;
  max-width: 100% !important;
  max-height: 100% !important;
}