html, body {
  width: 100%;
  height: 100%;
  overflow: hidden;
  margin: 0;
  padding: 0;
  -webkit-user-select: none;
     -moz-user-select: none;
      -ms-user-select: none;
          user-select: none;
}

* {
  -webkit-tap-highlight-color: rgba(255, 255, 255, 0);
}

body {
  background-color: lightgray;
}

#canvas {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  cursor: pointer;
}