gistfile1.css

#drop_overlay {
    display:none;

    background: rgba(0,0,0,0.75);
    color: #fff;
}

#drop_overlay span {
    font-size: 35px;
    text-align: center;
    position: absolute;
    left:25%;
    top:40%;
    width:50%;
    height:5%;

    text-shadow: 0px 0px 5px rgba(0, 0, 0, 1);
}

body.dragover #drop_overlay {
    z-index:90;
    display:block;
    position: fixed;
    top:0;
    right:0;
    bottom:0;
    left:0;

    width:100%;
    height:100%;
}