title: Rotating a background image with CSS3
body: <p>I have a background image that has an arrow that points to the right. When a user clicks on the button, the selected state changes the arrow to point down (using a different background position in my image sprite).</p>
  
  <p>Is there anyway to animate this using CSS3 so once the button is clicked and jQuery assigns it a "selected" class, it will rotate in an animation (only 90 degrees) from the right to down? (preferably using the single image/position with the arrow that points to the right)</p>
  
  <p>I'm unsure as to whether transform or key animation frames need to be used.</p>