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
alert(navigator.userAgent)
if(navigator.userAgent.indexOf("Firefox") > -1){
    $("#about_me").addClass("red");
}
else{    
    $("#about_me").addClass("blue");    
}