.photo_a{margin-bottom:30px;text-align:center}.photo_a .preview{position:absolute;top:50%;left:50%;transform:translate(-50%,-50%);width:89%;height:100%;background-color:rgba(60,63,70,.4);z-index:3;opacity:0;transition:all .35s;display:block}.photo_a .preview img{position:absolute;top:50%;margin-top:-25px;left:50%;margin-left:-25px;opacity:.8}.photo_a .preview:hover{opacity:1}.photo_a img{max-width:100%}