.star, .starfilled, .starempty, .starwaiting {
    display: block;
    width: 20px;
    height: 20px;
    background-image: url('../images/icons/star_darkgrey.png');
}
.starfilled {
    background-image: url('../images/icons/star_yellow.png');
}
.starwaiting {
    background-image: url('../images/icons/star_red.png');
}
.starempty {
    background-image: url('../images/icons/star_lightgrey.png');
}