@media (min-width: 768px) {
    .banner_about:before{
        width: 100%;
        content: "";
        height: 29.167vw;
        background-image: -webkit-linear-gradient(bottom, rgba(0, 0, 0, 0), rgba(0, 0, 0, 0.38), rgba(0, 0, 0, 0.6117647059), rgba(0, 0, 0, 0.8), #000000);
        z-index: 0;
        position: absolute;
    }
}



@media (min-width: 401px) and (max-width: 740px) {


    .banner_about:before {
        width: 100%;
        content: "";
        height: 44.167vw;
        background-image: -webkit-linear-gradient(bottom, rgba(0, 0, 0, 0), rgba(0, 0, 0, 0.38), rgba(0, 0, 0, 0.6117647059), rgba(0, 0, 0, 0.8), #000000);
        z-index: 0;
        position: absolute;
    }

}