.center {
	display: block;
	/*margin-left: auto;
	margin-right: auto;
	width: 50%;*/
}
.top {
	position: absolute;
	top: 0px;		
}

.book {	
width: 34%;
left: 33%;
top: 3vh;
position: absolute;
cursor: pointer;
}
.aperto {
width: 62%;
left: 18%;
top: 2vh;
position: absolute;
cursor: pointer;
}
.retro {	
width: 34%;
left: 33%;
top: 3vh;
position: absolute;
}
.penna {	
width: 4%;
left: 53%;
top: 15vh;
position: absolute;
transform: rotate(25deg);
}
.next{
width: 12%;
top: 72vh;
left: 87%;
position: absolute;
}