hi! i've been working on making my css, but i've run into a bit of a road bump: the chat box. everything else has been working well and is colored according to the coding, but no matter what i do to these specific lines, nothing changes. it's just default.

this is what i've been putting in:

.chat_light {background: rgba(220,111,167,0.8) !important;color: white !important;border: 1px solid white !important;text-align: left !important;}

.chat_dark {background: rgba(200,104,167,0.8) !important;color: white !important;border: 1px solid white !important;text-align: left !important;}

i've been working from mostly tutorials but these are the lines that i've seen so far. i even tried copy-and-pasting them and filling them out with my specific details. should i be trying something different? i'm very new to coding (started like 2 days ago) so i'm not sure what to do.

thanks in advance!