.alpha {
	position:relative;
	left:45%;
	background-colour:orange;
	display:inline-block;
}

.beta {
	position:relative;
	left:45%;
	display:inline-block;
	background-colour:blue;
	background-width:900px;
}

.gamma {
	position:relative;
	left:45%;
	display:inline-block;
}