#fullscreen-button {
  float: right;
  width: 38px;
  height: 38px;
  background: url('fullscr.png') no-repeat center;
}
#container { position: absolute }
#container.desktop { left: 50%; top: 50%; transform: translate(-50%, -50%) }
#container.mobile { width: 100%; height: 100% }
.mobile #canvas { width: 100%; height: 100% }
#footer { position: relative }
div{
 position: relative;
}

body{
  touch-action: pinch-zoom;
}

canvas{
   display: block;
   margin: 0 auto;
   width: 100vw;
   height: 100vh;
   position: absolute;
   top: 50%;
   left: 50%;
   background-color: transparent;
   transform: translate(-50%, -50%);
   -webkit-transform: translate(-50%, -50%);
   -ms-transform: translate(-50%, -50%);  
}