Using z-index CSS property on \'fixed\' positioned elements gives me a strange behavior under Chrome.
When Firefox and Opera browsers give me the awaited result, Chrome
I had some similar issues, and the only way to resolve I found was to apply some special styles to the webkit scrollbar in order to show it always. See http://jsfiddle.net/sinspiral/pTkQL/ with your example fixed.
This is not platform compatible (as on windows it will apply those styles too), so you might need to find a way, maybe js, to detect on which OS it is running.
.left::-webkit-scrollbar{
-webkit-appearance: none;
}
.left::-webkit-scrollbar-thumb {
background-color: rgba(50, 50, 50, .5);
border: 3px solid transparent;
border-radius: 9px;
background-clip: content-box;
}
.left::-webkit-scrollbar-track {
background-color: rgba(100, 100, 100, .5);
width: 15px;
}