JSFiddle - React, Tailwind, and code Playground

HTML

<div id="box">

CSS

#box{width:20px;height:20px;background:blue;}

JavaScript

$(function(){
  setInterval(function(){$("div#box").hide();},2001);
  setInterval(function(){$("div#box").show();},1000);
  });

$("div#box").on("DOMAttrModified",function(){if($(this).is(":visible"))console.log("visible");});