.sub_container{
    background: 50% 50% no-repeat;
        margin-top: 100px;
}
.sub_container_vision{
    min-height: 3563px;
    background-image: url(../images/sub/sub-vision.jpg);
}
.sub_container_product_detail{
    min-height: 5589px;
    background-image: url(../images/sub/sub-product-detail.jpg);
}
.sub_container_investment{
    min-height: 1158px;
    background-image: url(../images/sub/sub-investment.jpg);
}