Old question but nowadays CSS3 makes vertical alignment really simple!
Just add to #abc
the following css:
display:flex;
align-items:center;
Original question demo updated
Simple Example:
.vertical-align-content {_x000D_
background-color:#f18c16;_x000D_
height:150px;_x000D_
display:flex;_x000D_
align-items:center;_x000D_
/* Uncomment next line to get horizontal align also */_x000D_
/* justify-content:center; */_x000D_
}
_x000D_
<div class="vertical-align-content">_x000D_
Hodor!_x000D_
</div>
_x000D_