title: Sticky Header after scrolling down
body: <p>I saw this sticky header on this website:
  <a href="http://dunked.com/" rel="noreferrer">http://dunked.com/</a> <em>(no longer active, <a href="https://web.archive.org/web/20130815092145/http://dunked.com" rel="noreferrer">view archived site</a>)</em></p>
  
  <p>When you scroll down the sticky header comes down from the top.</p>
  
  <p>I looked at the code, but it looks really complicated. I only understand this:
  The normal header was cloned with JS and when you scroll down the page it animates from top.</p>