CSS selectors

Hello forum!

I've been reading a lot about modifying H5P CSS, adding handlers to PHP, but I just can't wrap a finger around it. My problem is that I have multiple text-area's in a video. I want to customise them seperately, but both text-area's have the same CSS selectors. How would I go about handing them different selectors so I can customise them seperately? Thanks!

Sincerely,

Luc