a:hover
 {
 background: #ffffff;
 
 }

 li a span
 {
 position: relative;
 font-size: 90%;
 font-weight: normal;
 text-align: left;

 }


 li a span span
 {
 display: block;
 position: absolute;
 visibility: hidden;
 top: 2em;
 left: .5em;
 padding: .2em .5em;
 width: 18em;
 background: #ffffff;
 border: solid #000000 2px;

 }

 li a:hover span span
 {
    visibility: visible;
 }