body {
    font-size: 15pt;
    user-select: none;
}
#red{
	position: absolute;
	width: 300px;
	height: 300px;
	
	
}
#green{
	position: absolute;
	width: 300px;
	height: 300px;
	visibility: hidden;
}
#button1{
position: absolute;
  top: 50%;
  left: 50%;
  margin: -150px 0 0 -150px;
}