ul {
	clear: both;
    font-family: Helvetica, Arial, sans-serif;
    list-style-type: none;
    position: relative;
    margin: 2em;
    padding: 1em;
}

ul li {
    position: relative;
    z-index: 200;
    padding: 0 0.5em;
    line-height: 1.5;
    float: left;
}

#navigation div.ahover {
    position: absolute;
}