body, html {
  margin: 0;
  padding: 0;
  overflow: hidden;
  width: 100%;
  height: 100%;
}

canvas {
  position: absolute;
  left: 0;
  top: 0;
  width: 100%;
  height: 100%;
  background-color: rgba(0, 0, 0, 0.2);
}

@media (max-width: 768px) {
  canvas {
    background-color: rgba(0, 0, 0, 0.3);
  }
}