JSFiddle - React, Tailwind, and code Playground

HTML

<div class="myClass"> 1 </div> 
<div class="myClass"> 2
    <p class="myClass"> 3 </p> 
    <p> 4 </p> 
    <p class="myClass"> 5 </p>
</div>

CSS

p { 
 color: black
}
.myClass { 
   color: red
}

JavaScript

document.onclick = function( ) {
   var e = document.querySelectorAll(".myClass");
   for( var i = 0, l = e.length; i < l; i++ ) {
      e[i].style.color = "green" 
   }
};