body {
	background-image: url("/images/clouds.jpg");
	background-repeat: no-repeat;
	background-position: center;	
}

.contenitore {
    position: relative;
    width: 98vw;
    height:98vh;
}

img{
	max-width: 50vh;
	max-height:50vw;	
	position:absolute;
	top:50%;
	left:50%;
	-webkit-transform: translate(-50%,-50%);
	-moz-transform: translate(-50%,-50%);
	-ms-transform: translate(-50%,-50%);
	-o-transform: translate(-50%, -50%);
	transform: translate(-50%,-50%);
}