JSFiddle - React, Tailwind, and code Playground

HTML

<html>
<head>
    <script>
         var treasure="";
function magic(obj){
    treasure=obj.target;
}
function domagic(){
    treasure.style.backgroundColor="red";
        document.getElementById("trg").innerHTML=treasure.innerHTML;
}
    </script>
</head>
<body>
<div  style="width:100px;height:100px;border:1px solid black">
  AAA  </div>
<div  style="width:100px;height:100px;border:1px solid black">
  BBB  </div>
<input type="button" onclick="domagic()" value="Do Magic">
    <span id="trg"></span>
     <script>
    document.onclick=function(e){magic(e)}; 
    </script>
</body>

</html>