.slider-thumb-img, .block-img{
    object-fit:cover;
    width: 100%;
}
@media (min-width: 768px) {
    .slider-thumb-img {
        height: 615px;
    }
    .block-img {
        height: 550px
    }
}

@media (max-width: 767px) {
    .slider-thumb-img {
        height: 190px;
    }
    .block-img {
        height: 260px
    }
}