.gallery {
 display: flex;
 flex-wrap: wrap;
 justify-content: center;
}

.gallery a {
    height: 200px;
    width: 300px;
    display: inline-block;
    overflow: hidden;
    border-radius: 4px;
    margin: 4px;
    -webkit-box-shadow: 0px 3px 10px 0px rgba(6, 6, 6, 0.67);
    box-shadow: 0px 3px 10px 0px rgba(6, 6, 6, 0.67);
}

.gallery img {
	-webkit-transition:  all .5s ease;
	-o-transition:  all .5s ease;
	transition:  all .5s ease;
}
.gallery a:hover img {
	opacity: 0.3;
	-webkit-transform: scale(1.1);
	    -ms-transform: scale(1.1);
	        transform: scale(1.1);
}
.gallery a:hover img:hover {
	opacity: 1;
}