JSFiddle - React, Tailwind, and code Playground

HTML

<br>
<div id="about_me">
This Text color will be change
</div>

CSS

.red
{
    color; red;
}

.blue
{
    color: blue;
}

JavaScript

// Show only on Firefox
<!--[if Gecko ]>
    
    $("#about_me").addClass("red");

<![endif]-->
   
// And   
    
<!--[ Other Browser, hide on Firefox ]>  
    
    $("#about_me").addClass("blue"); 

<![endif]-->