title: 45 degree angle split background colour for website
body: <p>Can anyone tell me the best way to get a scaling split background effect like this for a responsive website. Using in HTML5 and CSS3: <img src="https://i.stack.imgur.com/vIq1C.jpg" alt="Example background effect"></p>
  
  <p>I've tried a gradient but get a jagged edge and would appreciate any thoughts before I get too deep in to another method. Ideally has to work back to IE9.</p>
  
  <p>Thanks </p>