html,
body {
	height: 100%;            
}

.container {
	display: table;
	width: 100%;
	height: 100%;
	min-height: 100%;
	max-width: 540px;
	margin: auto;
}

.inner-container {
	display: table-cell;
	vertical-align: middle;
	max-width: 540px;
	margin: auto;
}