JSFiddle - React, Tailwind, and code Playground

HTML

<div id="navArea">
    <div id="navBar" class="noscript">
        <ul class="parent">
        <li class="active"><a href="#">Home</a></li>
        <li><a href="#">About</a></li>
        <li><a href="#">After Care</a></li>
        <li><a href="#">Repair</a></li>
        <li><a href="#">Store</a>
            <ul class="sub">
                <li><a href="#">Cat 1</a></li>
                <li><a href="#">Cat 2</a></li>
                <li><a href="#">Cat 3</a></li>
                <li><a href="#">Cat 4</a></li>
            </ul></li>
        <li><a href="#">Events</a></li>
        <li><a href="#">Community Service</a></li>
        </ul>
    <div id="movingBox">
        <div class="left"></div>
        <div class="middle"></div>
        <div class="right"></div>
    </div>
    </div>
</div>

<div id="mainContent">
</div>

CSS

#navArea{
height: 48px;
width: 100%;
background-color: grey;
background-repeat: repeat-x;
font-size: 15px;
font-family: 'BPreplayBold', Helvetica, Arial, sans-serif;  
}
#navBar {
margin-right: auto;
margin-left: auto;
position: relative;
width: 636px;
}
#navBar ul{
padding: 0;
margin: 0;
z-index: 20;
position: absolute;
}
#navBar ul li{
float: left;
list-style: none;
}
#navBar ul li a{
padding-left: 15px;
padding-right: 15px;
height: 45px;
display: block;
text-decoration: none;
text-align:center;
line-height: 45px;
color:  #EBEBEB;
}
#navBar ul li ul li{
width: 222px;
float: none;    
}
#navBar ul li ul li a{
padding: 0px 15px;
display:block;
height:25px;
line-height:25px;
background: url('../img/navBG.png');
background-repeat: repeat-x;    
}   
#navBar ul li ul li a:hover{
background: #2abcf2;    
}

#navBar #movingBox {
height: 46px;
width: 70px;
left: 0;
top: 0;
z-index: 19;
position: absolute;
}
#navBar #movingBox .left {
background-color: green;
float: left;
width: 7px;
height: 46px;
}
#navBar #movingBox .right {
float: left;
height: 46px;
width: 7px;
background-color: blue;
}
#navBar #movingBox .middle {

background-color: blue;
height: 46px;
float: left;
width: 56px;
}

JavaScript

$(document).ready(function() {
    $("#navBar").removeClass("noscript");
    $("#navBar ul.sub").hide();
    $("#navBar li").hover(function() {
        $(this).find('ul.sub').slideToggle(150);
    });
    $("#navBar li").mouseover(function() {
        hoverItemLeft = Math.round($(this).offset().left - $("#navBar").offset().left);
        hoverItemWidth = $(this).width();
        $("#movingBox").stop().animate({
            "left": hoverItemLeft,
            "width": hoverItemWidth
        }, 350, 'easeOutBack');
        $("#movingBox .middle").stop().animate({
            "left": hoverItemLeft,
            "width": hoverItemWidth - 17
        }, 350, 'easeOutBack');
    });
    $("#navBar").mouseleave(function() {
        activeItemLeft = Math.round($("#navBar li.active").offset().left - $("#navBar").offset().left);
        activeItemWidth = $("#navBar li.active").width();
        $("#movingBox").stop().animate({
            "left": activeItemLeft,
            "width": activeItemWidth
        }, 350, 'easeOutBack');
        $("#movingBox .middle").stop().animate({
            "left": hoverItemLeft,
            "width": activeItemWidth - 17
        }, 350, 'easeOutBack');
    });
});