#scrolltop
{
    position: fixed;
    right: 10px;
    bottom: 10px;
    width: 38px;
    height: 36px;
    opacity: 0;
    z-index: -1;
    filter: alpha(opacity=0);
    -ms-filter: "progid:DXImageTransform.Microsoft.Alpha(Opacity=0)";
    -webkit-transition: opacity 400ms ease;
    transition: opacity 400ms ease;
    background-color: rgba(0, 0, 0, 0.2);
    border-radius: 3px;
    border:1px solid rgba(100,100,100,0.3);
}

#scrolltop:before
{
    color:#FFF;
    display: block;
    width: 37px;
    height: 36px;
    content: "";
    background-image: url("data:image/gif;base64,R0lGODlhFgAWAMIEAObm5ufn5/f39/j4+P///////////////yH5BAEKAAcALAAAAAAWABYAAANAeLrc/jBGAOQkpNoGMBbb0g0eAW7jgR3keQ3KyprvIs9uQ8A2wZAhlS+oGxJ7R8YtuTw2ic9gNDTdVC2BQJKYAAA7");
    background-repeat: no-repeat;
    background-position: center center;
}

#scrolltop:hover
{
    background-color: rgba(0, 0, 0, 0.5);
}

#scrolltop.on
{
    right: 10px;
    opacity: 1;
    z-index: 109;
    filter: alpha(opacity=100);
    -ms-filter: "progid:DXImageTransform.Microsoft.Alpha(Opacity=100)";
}