#stacks_in_21 {
	background-color: rgba(0, 0, 0, 0.30);
	margin: 30px 0px 30px 0px;
	padding: 70px 40px 70px 40px;
}

#stacks_in_18 {
	margin:  20px;
	padding:  20px;
}

#stacks_in_8 {
	margin:  20px;
	padding:  20px;
}