html,body {
    margin: 0;
    padding: 0;
  background: #222;
}
main {
    text-align: center;
    width: 100%;
}
canvas {
  display: block;
}
main {
  align-items: center;
  display: flex;
  height: 100vh; 
  justify-content: center;
}
main canvas { 
  height: auto !important;
  width: auto !important;
  max-width: 100%;
  max-height: 100%;
  display: inline-block; 
  margin: 0 auto;
  vertical-align: middle;
  touch-action: none;
}