JSFiddle - React, Tailwind, and code Playground

HTML

<div class="container">
	    <p>Demo of Callback Function in jQuery</p>
	    <div style="text-align:center;"><button type="button">Click me</button></div>
	</div>

CSS

p{
        background:grey;
        max-width: 500px;
        font-size: 24px;
        padding:40px 20px;
        border:2px solid black;

    }
    .container{
    	max-width:500px;
    	margin:0 auto;
    }
    button{
    	background:;
    	border:1px solid black;
    	padding:5px 4px;
    	border-radius:12px;
    }

JavaScript

$(document).ready(function(){
    $("button").click(function(){
        $("p").slideToggle("slow", function(){
            alert("The slide toggle effect has completed.");
        });
    });   
});