.button img{
    position: absolute;
    height: 50px;
    z-index: 3;
    vertical-align: middle;
}
.item{
    position: absolute;
    display: none;
}
.active{
    display: block;
}
.desc{
    background-color: rgba(200, 200, 200, 0.85);
    width: 620px;
    position: absolute;
    /*bottom: 100px;*/
    padding: 10px;
}