JSFiddle - React, Tailwind, and code Playground

HTML

<div id="greenn31"></div>

CSS

#greenn31{
    background-color:#093;
    float: left;
    height: 25px;
    width: 25px;
    margin-left: 544px;
    margin-top: 51px;
    position:absolute;
    visibility:hidden;
}

JavaScript

if (!$("#greenn31").css('visibility') === 'hidden') {
  alert ("visible");
  document.getElementById("greenn31").style.visibility = "visible";
  //source3 = source3 - node31;
}else{
	alert('hidden');
}