title: CSS Background syntax issue
body: <pre><code>background: url('../city-lights.jpg') no-repeat fixed center center / cover  transparent;
  </code></pre>
  
  <p>How does that code work?
  I get that no-repeat stops the bg image from repeating, fixed means it's fixed to it's position, center center means it's centered along the x and y axes, cover means it'll cover the whole screen even if it has to stretch or shrink for it, and transparent renders it transparent.</p>
  
  <p>What does the '/' do? Why's it there?
  In case anyone thinks, this is a perfectly legit code that works, but not written by me.
  Also, in case someone wonders, I did not know what to google, I tried something, it didn't give back helpful results.</p>