This is the 3210th most frequent Portuguese word.
curta
"Curta" means "short" or "brief" and can also refer to a "short film."
In this sentence, 'curta' is the command form (imperative) of the verb 'curtir', used to mean 'enjoy' or 'make the most of' something.
Curta o seu dia ao máximo!
Enjoy your day to the fullest!
Here, 'curta' functions as an adjective meaning 'short', describing the type of film ('filme').
Ela quer assistir a um filme curta neste final de semana.
She wants to watch a short film this weekend.
In this usage, 'curta' is the subjunctive form of the verb 'curtir', expressing hope or wish regarding the enjoyment of something.