.about-img{
    background: url(../images/om-oss.jpg);
    height: 100%;
    width: 55%;
    background-size: cover;
    background-position: center right;
    grid-row: span 2;
    position: absolute;
    right: 0;
}



@media(max-width: 840px){

    #section3, .container div:first-child{
        grid-row: 1;
    }

    .about-img{
        display: none;
    }
}