#field_productcates{
    margin-top: 50px;
}
#field_productcates .item-inner .left-block a.product_img span.img_root:before {
    background-color: transparent;
    content: "";
    height: 100%;
    left: 0;
    margin: auto;
    position: absolute;
    top: 0;
    transition: all 0.3s ease-out 0s;
    width: 100%;
}
#field_productcates .item-inner:hover .left-block a.product_img span.img_root:before {
    background: #555 none repeat scroll 0 0;
    content: "";
    height: 100%;
    left: 0;
    margin: auto;
    opacity: 0.3;
    position: absolute;
    top: 0;
    transition: all 0.3s ease-out 0s;
    width: 100%;
}