Chrome doesn't respect the z-index order
Sometimes z-index can be a bit tricky. This article from the W3 may be of some help. But that spec may be a bit confusing. If I can't get z-index to work, then I make sure that my elements in the DOM are ordered properly. Generally elements lower in the DOM, have a higher visibility preference. So under some conditions, this might be true:
<div style="z-index:9999">I'm on bottom</div><div>I'm on top</div>Try reordering the elements in the DOM.