title: Why does this technique commonly use negative text-indent?
body: <p>Let's say you want to replace an anchor with an image, and you make that image the anchor's background. You still want the text wrapped by the anchor to be there for accessibility reasons, but you don't want it visible. A well known technique is to use something like text-indent: -9999px; along with overflow: hidden;</p>
  
  <p>So let's say our anchor box is 50px x 50px, why wouldn't we just do text-indent: 50px? This would shove the text into the hidden overflow of the anchor, <em>no matter how long it gets!</em></p>