This CSS customization didn’t work.
I suggest upgrading to the latest release.
Also, when creating a new ticket, the datepicker is also not translating to Brazilian Portuguese.
I can assure you that the datepicker is translating properly.
I’m afraid that the problem is that the Brazilian Portugese language pack is missing a lot of translations… it is only 17% complete!
https://crowdin.com/project/osticket-official
You may consider opening a Crowdin account and contributing.