/* commons */

.dim{/*默认是灰色的星星*/
    float: left;
    width: 20px;
    height: 20px;
    background: url('../img/start1.png');
    background-size: 100%;
}
.highlight{/*评论是几就会点亮几颗星星*/
    float: left;
    width: 20px;
    height: 20px;
    background: url('../img/start2.png');
    background-size: 100%;
}