Update outdated CSS snippets in custom-css.md (#238)
Update outdated CSS snippets in custom-css.md (#238)

Co-authored-by: Max Leiter <9c23837b173eedf44009e9f92676105ffaeaaf32@usc.edu>
thelounge/thelounge.github.io,thelounge/thelounge.github.io,thelounge/thelounge.github.io