No AJAX happens here. The <a>(display: none;) is located within an <aside> which also contains an <h3>(visible). When a visitor hovers over the <div> that contains the <aside>(dark grey), the <a>, which is absolutely positioned relative to the <body>, centers depending on its width and fades in.
Centering relative to current <body> width is important because this is a responsive design, as you can see by resizing your browser window.
I don't want the math and css to occur on mouseleave; I just want it to fade out -- hence no use of .hover.
<style>
#branding .widget-area aside > a {
display: none;
position: absolute;
right: 50%;
z-index: 10;
padding: 5px;
- }
<header id="branding">
<hgroup><h1>quack</h1><h2>quack quack</h2></hgroup>
<div class="widget-area">
<h3>Quotation</h3>
<a><div><div><img /></div></div></a>
</aside>
</div>
</header>
P.S. The editor's font color picker does not function correctly, at least not in Opera 12.02