#displayDIV {
	display:none;  
	background-color:silver; 
	width:100vw; 
	height:100vh; 
	position:absolute; 
	text-align:center;
	top:0px; 
	left:0px;
}

#displayDIV img.bigIMG {
	margin-top: 20px;
	height: calc(100% - 70px);	
	}