Vertical Center

<div style="width: 100%; height: 100%; display: table; text-align: center;">

<div style="display: table-cell; vertical-align: middle;">

<div style="display: block; margin: 0 auto;">

<div style="width: 300px; display: block; height: 300px; border: 1px solid #000; margin: 0 auto">

"the box".

<!--.

The box stays centered vertically and horizontally while its size.

Changes (or while the window size changes) without the need to.

Specify widths or heights anywhere.

Less javascript - annoying extra divs = a smoother ride overall.

-->.

<div </div>

<div </div>

<div </div>

<div </div>