.flex-images { overflow: hidden; position: relative; }
.flex-images .item { float: left; margin: 5px; background: #eee; box-sizing: content-box; overflow: hidden; position: relative;  }
.flex-images .item img { display: block; width: auto; height: 100%; max-width: none; }
.flex-images .item .caption { position: absolute; bottom: 0; left: 0; right: 0; padding: 4px 6px; font-size: 13px; color: #fff; background: #222; background: rgba(0,0,0,.7); }
.flex-images .item .caption { 
    -webkit-transform: scaleY(0);
    -o-transform: scaleY(0);
    -ms-transform: scaleY(0);
    transform: scaleY(0);
    -webkit-transform-origin: bottom;
    -o-transform-origin: bottom;
    -ms-transform-origin: bottom;
    transform-origin: bottom;
    -webkit-transition: -webkit-transform 0.26s ease-out;
    -o-transition: -o-transform 0.26s ease;
    -ms-transition: -ms-transform 0.26s ease;
    transition: transform 0.26s ease;
}
.flex-images .item:hover .caption { 
    -webkit-transform: scaleY(1);
    -o-transform: scaleY(1);
    -ms-transform: scaleY(1);
    transform: scaleY(1);
}