.productRate {
    background: url(../image/stars.png);
    width: 160px;
    height: 32px;
    position: relative;
    background-size: auto 300%;
}
.productRate div {
    background: url(../image/stars.png) left bottom;
    background-size: auto 300%;
    width: 0;
    height: 100%;
    position: absolute;
    top: 0;
    left: 0;
    z-index: 1;
    cursor: pointer;
}
.productRate.nochange div {
    cursor: auto;
}
.productRate span {
    display: block;
    height: 100%;
    position: absolute;
    top: 0;
    left: 0;
    z-index: 2;
    background: url(../image/stars.png) left center;
    background-size: auto 300%;
    width: 0;
    cursor: pointer;
}