title: Design patterns/tools for a HTML app with a reactive layout?
body: <p>We're building a website with app versions that will (initially) be HTML driven. 
  We want the same document to be rendered with varying layouts and styles depending on: client device/browser, width/height, PPI, aspect ratios.</p>
  
  <p>e.g. Check out SquareSpace and make your browser smaller/bigger, wider/taller: <a href="http://www.squarespace.com/" rel="nofollow">http://www.squarespace.com/</a></p>
  
  <p>What's a good set of tools or design patterns for constructing a reactive web client? </p>