title: How can a variable-height sticky footer be defined in pure CSS?
body: <p>The key to note here is the height of the footer is not going to be fixed, but will vary with its content.</p>
  
  <p>When I say “sticky footer,” I use it in what I understand to be the common definition of “a footer that is never higher than the bottom of the viewport, but if there is enough content, it will be hidden until the user scrolls down far enough to see it.”</p>
  
  <p>Note also I don’t need to support legacy browsers. If CSS <code>display: table</code> &amp; related properties help here, they are fair game.</p>