.flex-images {  }
.flex-images .item { float: left; margin: 4px; border: 1px solid #eee; box-sizing: content-box; position: relative;  }
.flex-images .item img { display: block; width: auto; height: 100%; }

.flex-images-slider
{
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
}
.flex-images-slider .item { float: left; margin: 4px; border: 1px solid #eee; box-sizing: content-box; position: relative;  }
.flex-images-slider .item img { display: block; width: auto; height: 100%; }

@media(max-width:1200px)
{
    .flex-images-slider
    {
        display: flex;
        flex-wrap: wrap;
    }
}