.banner-wrapper{
    width: 100%;
    height: 400px;
    position: relative;
}
.banner-bg{
    background:url("http://media.xitaoinfo.com/web_ppa-banner-bg.jpg") no-repeat center;
    width: 100%;
    position: absolute;
    left: 50%;
    height: 100%;
    margin-left: -50%;
}
.img1{
    margin: 0 auto;
    width: 1200px;
    height: 833px;
    background: url("http://media.xitaoinfo.com/web_padv-img1_1.jpg")0 -1px no-repeat;
}

.img2{
    margin: 0 auto;
    width: 1200px;
    height: 770px;
    background: url("http://media.xitaoinfo.com/web_padv-img2_1.jpg")no-repeat center;
}

.img3{
    margin: 0 auto;
    width: 1200px;
    height: 698px;
    background: url("http://media.xitaoinfo.com/web_padv-img3_1.jpg")no-repeat center;
}

.img4{
    margin: 0 auto;
    width: 1200px;
    height: 1200px;

}

.img5{
    margin: 0 auto;
    width: 1200px;
    height: 605px;
    background: url("http://media.xitaoinfo.com/web_padv-img5_1.jpg")no-repeat center;
}