Then add parent class, I've added .bx-tl-item-raw by Timeline and it works so:
.bx-tl-item-raw .bx-polls-embed { height: 400px; }
thx again for your help!, but sorry, no success
Sorry for the obvious question - but did you clear the cache after your changes?
it is not that obvious as it seems to be 😎 but yes, cache was cleared
