So I managed to customise the look of the chat box on my den page to fit the theme I was going for, along with every button on the page. I then wanted to use the same theme on all pages that let you use custom CSS, branch page, caves, and mounds, so I just linked the same .css file from my dropbox and everything worked exactly as I expected (for the branch I had to add some stuff because there are elements which don't exist on den page), apart from the chat box and some random buttons.

My question is this: has anyone been able to use CSS to customise the chat box and roar button on cave and branch pages or is this not something we can do for whatever reason?

Here are screenshots of the chat box on my den page and then on my branch page, different despite using the same .css file: