body {
	overflow: hidden;
    background-color: #ccc;
    margin: 0px;
    padding: 0px; 
}

a#pdf{
    top: 47%;
    left: 50%;
    width: 147px; 
    height: 162px;
    margin: -81px 0px 0px -74px; 
    background: transparent url(../img/pdf_icon.png) no-repeat left center;
    display: block;
   	z-index: 9999;
    text-indent: -9999px;
    position: absolute;
    outline-style: none;
}

a#pdf:hover{
    background-position: right center ;
}