html, body {
  width: 100%;
  height: 100%;
}
body {
  margin: 0;
  display: flex;
  background-color: #E9E7E9;
  font-size: 0;
  justify-content: center;
  align-items: center;
  background-image: radial-gradient(#E9E7E9, #C4C3C5);
  font-family: sans-serif;
}
canvas {
  border-radius: 2px;
  background-color: black;
  -webkit-tap-highlight-color: transparent;
}