JSFiddle - React, Tailwind, and code Playground

HTML

<div id="menu" class="margint10 round-border">
                <a href="#"><img src="https://dl.dropbox.com/u/19982181/fab/plus.jpg" alt="" id="menu_link"/></a>
            </div>
<div class="flyout hidden">&nbsp;</div>

CSS

.flyout{
position:absolute;
width:1000px;
height:450px;
background:red;
overflow: hidden;
z-index:10000;
}
.hidden{
display:none;
}

JavaScript

$("#menu").hover(function(){
    $('.flyout').slideToggle();
});