#waterfall{ text-align:center; width:965px; margin:0 auto;}
#waterfall img{ width:200px;}
#waterfall .cell{ padding:5px; width:200px;border:1px solid #E3E3E3; background:#fff; margin-top:20px;box-shadow: 0px 2px 3px 1px #ccc;}
#waterfall .cell:hover{box-shadow: 0px 2px 3px 1px #999;}