z-Index problem?


I’ve got a custom coded element which give the ability for the user to draw on-screen with the mouse.
My element is .drawing-container in my project.

I’ve got 2 issues.

Issue #1 -
The drawing-container needs to be displayed below the content-container (for the drawings to don’t hide the content).
I tried several things, BUT can’t figure out what’s the problem in my project.
If i change z-indez, i can’t draw anymore.

Issue #2 -
To be able to draw, i need to resize the window. I don’t have the same problem when there’s no content-containers. Any idea how to fix this ?

Here is my site Read-Only: LINK