body {
       margin:0; padding:0;
   }
   html, body, #bg {
       height:100%;
       width:100%;
   }
   #bg {
       position:absolute;
       left:0;
       right:0;
       bottom:0;
       top:0;
       overflow:hidden;
       z-index:0;
   }
   #bg img {
       width:100%;
       min-width:100%;
       min-height:100%;
   }
   #content {
       z-index:1;
   }

body {
  align-items: center;
  display: flex;
  height: 100vh; /* Fallback for browsers that do not support Custom Properties */
  height: calc(var(--vh, 1vh) * 100);
  justify-content: center;
  background: #050505;
}
body,
html {
  margin: 0;
  overflow: hidden;
  padding: 0;
}
canvas {
  display: inline-block; /* Instead of display: block; */
  margin: 0 auto;
  max-width: 100%;
  max-height: 100%;
  touch-action: none;
  vertical-align: middle;

  height: auto !important;
  width: auto !important;
}