How do I make confetti

/*page confetti*/

html:before {

  animation: grain 30s steps(10) infinite;

  background-image: url(https://cdn.shopify.com/s/files/1/0107/4751/0884/products/Confetti3_250x250@2x.gif?v=1574208137);

  content: "";

  height: 300%;

  left: -50%;

  opacity: .50;

  position: fixed;

  top: -110%;

  width: 300%;

  pointer-events:none;

}

@keyframes grain {

  0%, 100% { transform:translate(0, 0) }

  10% { transform:translate(-5%, -10%) }

  20% { transform:translate(-15%, 5%) }

  30% { transform:translate(7%, -25%) }

  40% { transform:translate(-5%, 25%) }

  50% { transform:translate(-15%, 10%) }

  60% { transform:translate(15%, 0%) }

  70% { transform:translate(0%, 15%) }

  80% { transform:translate(3%, 35%) }

  90% { transform:translate(-10%, 10%) }

}