span.image_row
{
overflow: hidden;
}

span.image_item
{
float: left;
text-align: center;
}

span.image_thumbnail
{
width: 100%;
height: 100%;
margin-bottom: 5px;
float: left;
background-repeat: no-repeat;
background-position: center center;
}
div.image_thumbnails {margin-top:20px;}
div.image_thumbnails ul li img {vertical-align:-4px;}
div.image_thumbnails ul li {margin-bottom:5px;}