I'm changing the way a website looks by using CSS, and creating a userstyle for this webpage. (Among others in its domain.)
Check out the button and its popup right next to it in this image.
I want to change the way that popup iframe looks. But as you can see in
this screenshot of Chrome's developer inspection tool, the src property of the iframe is unknown:
<iframe id="cke_48_frame" class="cke_panel_frame" role="presentation" frameborder="0"src(unknown)>
As far as I've searched Google and Stack Overflow, I found that I have to apply CSS to the actual webpage that the iframe contains. But how can I know the webpage within the iframe when the src property is unknown?
I couldn't find any info about how I can deal with this problem.
Any help would be appreciated.