.hero__img{

   background-attachment: fixed;
}
.hero__img-item img{
    display: none;
}
.hero__img-item--mobil img{
    width: 100%;
        display: block;
}


@media (min-width: 768px){
    .hero__img-item img{
        width: 100%;
        display: block;
    }
    .hero__img-item--mobil img{
        width: 100%;
            display: none;
    }
    
    
}