Edit in JSFiddle

* {
    padding: 10px 20px;
}
.container {
	position: relative;
	height: 6em;
    width: 300px;
	background: #e5e6e5;
    margin-left: auto;
    margin-right: auto;
}
.content {
	position: absolute;
    color: #fff;
	top: 3em;
	line-height: 3em;
	margin-top: -1.5em;
	background: #7396a1;
}

<div class="container">
	<div class="content">I'm aligned vertically!</div>
</div>