main .promocion{
    height: 100vw;
    max-height: 600px;
    grid-column: 1/-1;
    position: relative;
    margin-top: 35px;
    background-image: url(../imagenes/promoCel.jpg);
    background-size: auto 100%;
    background-repeat: no-repeat;
    background-position: 0% 50%;
    background-color: blue;
}


@media only screen and (min-width: 760px){
  main .promocion{    
    max-height: 500px;
    background-size: 100% auto;
    background-image: url(../imagenes/promoPc.jpg);
    margin-top: 0px;
  }
}