Fixing Popup On My Page

[TuneToyz]

https://tunetoyz.com/?popup-preview=true&popup-id=NjExOTA=

Hello! I’ve included a link to my popup above, which has an issue. I don't want the background to completely cover the image. Instead, I'd like some padding so the image can be visible within the popup, similar to the example attached below. Is there any CSS code I can add to achieve this? Thank you!

 

[TuneToyz]

where do I add it?

[TuneToyz]

Nevermind I found it thanks 

[TuneToyz]

is there a way to make it more like a  square shape? 

[TuneToyz]

like smaller