#ex4 img {
    margin-bottom: 10px;
    /*border: 4px solid #eee;
    -webkit-box-shadow: 4px 4px 4px rgba(0,0,0,0.5);
    -moz-box-shadow: 4px 4px 4px rgba(0,0,0,0.5);
    box-shadow: 4px 4px 4px rgba(0,0,0,0.5);
    -webkit-transition: all 0.4s ease-out;
    -moz-transition: all 0.4s ease;
    -o-transition: all 0.4s ease;*/
}
 
#ex4 img:hover {
    -webkit-transform: rotate(-10deg);
    -moz-transform: rotate(-10deg);
    -o-transform: rotate(-10deg);
	z-index:99;
}