title: Can I use a MutationObserver to listen for changes on computed styles?
body: <p>Can I use a MutationObserver to listen for changes on computed styles? I have a div which width is 100% and I'd like to know when its computed width changes, but so far no success. The MutationObserver works if I change the style pragmatically:</p>
  
  <p><code>document.getElementById("myDiv").style.width = "200px"</code></p>
  
  <p>But it doesn't work if the interface is resized by a window resize or if a parent div resizes.</p>
  
  <p>Any solution that doesn't involve timeouts?</p>
  
  <p>UPDATE: I'm particularly interested in a solution that also wouldn't involve listening to window resize event, because sometimes the interface changes without the window resizing. For instance, a div that has a percentage as width and a parent node size changes.</p>