How to create a CSS theme for the LG WebOS app?

[Kahan Bhalani]

I would like to customize the CSS for the Jellyfin app on WebOS. I tried modifying some properties like font and layout but they don't seem to apply on the TV. They work fine on the web version of Jellyfin on Windows.

Is there any specific class which I need to apply for TV? If anybody has tried this before, please let me know.

[James.Ashwin]

In my experience most if not all of my alterations carry over. From my understanding webOS supports CSS3 HTML5 and JavaScript natively.