Can’t get transparent page to show background image

Hi,

I’ve read a lot of topics in this forum and tried multiple “solutions” but I still can’t make a simple thing like adding a background to a page and have the content of that one page transparent.

I can change the background color with custom css, but when trying transparent either with word, rgb or hex it does not work.
I can also set a background through custom css, but then it’s set on all pages but I’d like different backgrounds on different pages… is this possible by adding custom css?

I need this thing sorted or I’m afraid HB won’t be any good for me and I’d like a refund of my purchase. Adding a background image with transparent boxes over is something I’d assumes was a basic functionality in a modern theme.

Best regards,
Daniel