* {
  -webkit-tap-highlight-color: rgba(0, 0, 0, 0);
}
html {
  height: 100%;
  overflow: hidden;
  background: url("bg.png");
  background-attachment: fixed;
  background-size: cover;
}
canvas {
  position: absolute;
  left: 0px;
  right: 0px;
  top: 0px;
  bottom: 0px;
  margin: auto;
}