title: How does the Stack Overflow Search Input work?
body: <p>How does the stack overflow search input at the top works? It seems to expand random or when it's empty and backspace is hit.</p>
  
  <ol>
  <li>What is the jQuery, html and css behind it?</li>
  <li>Does it replace or expand over the links?</li>
  <li>Is there an other additional functionality I've missed?</li>
  </ol>