JSFiddle - React, Tailwind, and code Playground

HTML

<canvas id="ctxt" width="500" height="500"></canvas>

JavaScript

var cvas = document.getElementById("ctxt");
var cx = cvas.getContext("2d");
    cx.fillStyle = "rgba(0,0,0,1.0)";
    cx.fillRect(200,200,300,300);
setInterval(function(){
cx.fillStyle = "rgba(255,255,255,0.2)"
cx.fillRect(0,0,500,500);
},10);