I have a tricky question: I have a fullsize background over the site I\'m working on. Now I want to attach a div to a certain position on the image and also that the div sc
A far simpler/better approach to you problem is to use an SVG element, it is better suited to your requirement. The cool thing about SVG is everything will scale proportionally by default because it is a vector object not a document flow object.
This example will demonstrate the technique
SVG
You can add images to SVG to achieve what you need.
https://jsfiddle.net/tnt1/3f23amue/