JSFiddle - React, Tailwind, and code Playground

HTML

<div id="menu">

</div>

CSS

*{
	padding:0;
	margin:0;
}
#menu{
	position:absolute;
	width:5px;
	height:100%;
	background:#4d4d4d;	
}

JavaScript

$(document).ready(function () {

           $("#menu").hover(function () {

               $("body").children(':not(#menu)').css("-webkit-filter", "blur(1px)");
               $(this).stop().animate({
                   width: "200px"
               },250);
               if ($('#menu').width() == '200px') {
                   alert("what");
               }
           }, function () {

               $(this).stop().animate({
                   width: "5px"

               },250);
               $("body").children(':not(#menu)').css("-webkit-filter", "none");
           });
       });