body{
  margin:0;
  overflow: hidden;
  background:black;
}
canvas{
  position: absolute;
  top: 0;
  left: 0;
}
#downloadButton{
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height:100%;
}
.cr.function{
  position: relative;
}