@media screen and (max-width:991px){#testimonial_section{
    overflow: hidden
}
#testimonial_section:before{
    position: absolute;
    content: "";
    background: url("https://designingmedia.com/wordpress/hostiko/layout39/wp-content/uploads/2020/04/oval-_shape.png") no-repeat;
    width: 100%;
    height: 100%;
    left: 0;
    right: 0;
    top: -160px;
    margin: 0 auto
    
}

}