I\'ve looked at many \"mysterious white-space at bottom of page\" issues here on SO, and played with the viewporttag many times, but I still cannot figure out w
What's going on here:
width=device-width, this makes the layout size on your page equal to the device's screen width. i.e. making an element 100% will give it the same width as the screen.device-width/aspect ratio pixels, which doesn't fill the zoomed out viewport.The correct way to fix this is to make sure all your content is contained by the layout size. In your case, the reason the sub_container_div is wider than the layout size is that your padding/margins cause it to expand outside the parent. The solution is to add box-sizing: border-box to the sub_container_div and dialog elements and width: 100% to sub_container_div. That way, Chrome can't zoom out and you can't see outside the layout box (in HTML spec language, that's the initial containing block).