.gallery__img-wrapper {
    opacity: 1;
    transition: opacity .3s;
}

.gallery__img-wrapper:hover,
.gallery__img-wrapper:focus {
    opacity: .9;
}

.gallery__img-grid {
    padding-top: 7.5px;
    padding-bottom: 7.5px;
}

.gallery__img-wrapper img {
    max-width: 100%;
    max-height: 100%;
}