Drop Shadow on 3 Sides

#shadow-three-sides {
-moz-box-shadow: 0px 7px 5px -2px blue, 7px 0px 5px -2px red, -7px 0px 5px -2px green;
-webkit-box-shadow: 0px 7px 5px -2px blue, 7px 0px 5px -2px red, -7px 0px 5px -2px green;
box-shadow: 0px 7px 5px -2px blue, 7px 0px 5px -2px red, -7px 0px 5px -2px green;
}

http://blog.grio.com/2012/02/a-quick-reference-on-box-shadows.html