:root {
    --img_ratio3783: 16/9; 
}

#s3{
    aspect-ratio: var(--img_ratio3783);
}

.img3783{
    background-image: url(../../img/3783.jpg);
    aspect-ratio: var(--img_ratio3783);
}

/*----- MOBILE -----*/
@media only screen and (max-aspect-ratio: 1/1){
    .img3783{
    }
}