title: How to get Bootstrap's "hero-unit" to fit across the entirety of top section?
body: <p>I am currently learning Rails and CSS, and am trying to replicate the look of Bootstrap's <a href="http://twitter.github.com/bootstrap/index.html" rel="nofollow">github page</a> as a learning exercise.  Bootstrap's central unit (purpleish colored, and contains the big header "Bootstrap") fits across <em>all</em> of the top of the page, having no white space on the side.  However, my current attempt looks more like this <a href="http://twitter.github.com/bootstrap/examples/hero.html" rel="nofollow">example page</a> where the central grey unit containing "hello world" is itself a box, and with white space surrounding it.  Basically, my question is, how would I make that whitespace disappear?  I have attempted to emulate what is shown in the page's source, but am still getting this outcome.</p>
  
  <p>Thanks!</p>