Easiest way to vertical align text - link within a box

So you want to center align a div within a div but it does not work as expected? for example this solution http://codepen.io/Tipue/pen/vsKif did not work out for my divs.
  text-align: center;
  display: table;
  height: 100%;
  width: 100%;
  background: rgba(0,0,0,0.4);
a span{
  display: table-cell;
  vertical-align: middle;
No problemos! we call the "old" table solution to the rescue. Setting display of parent as a table and then the child as table-cell did the trick. Enjoy!
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