Is it possible to hide an element in İFRAME?

Question

I am using an İFRAME on my site tuning-doc.nl to select car makes with their horsepower. I would like to hide the following:

Powered by Tuning-shop.com

At the top and the bottom. I tried to hide these by CSS in Google Chrome's inspector, but when I save in via the customizer of WordPress's theme, nothing happens and the text is still there.

Can you help me please?

I tried it to hide it through CSS. But it is still there. Inspector is working, but theme not.

Answer 1

This should do the job:

 .Top__right.header-color { display: none;}

But if it does not work you can try:

.Top__right.header-color { display: none !important;}

Answer 2

Styles for your site cannot impact elements inside of iframes that are cross-domain. Cross-domain websites embedded in iframes are isolated from your site.