Hi David. You have already asked a question about your layout. And I wrote to you that it is not possible to tie the background image to the elements. The background image lives its life. I'm afraid you will have to review your design and redo it. On any other screen size that differs from your laptop, this will turn into chaos. The same on "Cat" page.
I hope this picture will help to realize how the background image works.

The creation of such a layout so that it is responsive not possible with standard SPPB means. This will require significant CSS skills additionally. And not every professional will be able to do this.