<div class="layer">
  <span class="content">Layer Contents</span>
  <span class="blank"></span>
</div>
body{background:#ccc}
.layer{position:absolute;top:0;left:0;width:100%;height:100%;text-align:center}
.layer .content{display:inline-block;background:#f00;vertical-align:middle}
.layer .blank{display:inline-block;width:0;height:100%;vertical-align:middle}
Rerun