JSFiddle - React, Tailwind, and code Playground

HTML

<div id="something"></div>
<input id="btn_test" type="button" value="Test Button(Works!)"/>
<input id="btn_test2" type="button" value="Test Button(Nope...)"/>
<input id="btn_test3" type="button" value="Test Button(Nope...)"/>

CSS

#something {
    width: 100px;
    height: 100px;
    background: #000;
    display: none;
}

JavaScript

$(function (){
    
    $('#btn_test').click(function (){
        
        var something = $("#something")
            .css({backgroundColor: 'red'})
            .show()        
        setTimeout(function(){
            something.css({backgroundColor: ''});
        },2000);
    
    })

})