body, html {
  margin: 0;
  padding: 0;
  overflow:visible; 
  width: 100%;
  height: 100%;
  z-index: -10;
  opacity: 0.9;
}

canvas {
  display:grid;
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  z-index: -10;
  opacity: 0.5;
}