.banner_product {
    background: url(../images/product.jpg) no-repeat 0 0/100%;
}

.adlunbotu {
    position: relative;
    width: 1800px;
    margin: 0 auto;
    margin-top: 60px;
}
.adlunbotu img {
    width: 1800px;
    height: 442px;
}
.prev, .next {
    position: absolute;
    top: 0;
    bottom: 0;
    margin: auto;
    width: 57px;
    height: 57px;
    background-color: transparent;
    border-radius: 50%;
    border: #e1e1e1 3px solid;
    line-height: 57px;
    text-align: center;
    font-size: 25px;
    font-weight: 700;
    color: #bfbfbf;
}
.prev {
    left: 165px;    
}
.next {
    right: 165px;    
}