Is the word culturais the same in Brazilian and European Portuguese?

Yes

The word "culturais" is identical in spelling, meaning, and grammatical function in both Brazilian and Continental Portuguese. The only difference lies in pronunciation.

In Brazilian Portuguese, the vowels are generally more open and the rhythm is more "syllable-timed," making the unstressed "u" in "culturais" clearly audible. In Continental Portuguese, there is a significant phenomenon of vowel reduction; unstressed vowels are often closed or nearly swallowed, making the word sound more "consonant-timed" and the "u" much more subtle.

Brazilian Portuguese Examples

1. As manifestações culturais do Brasil são muito ricas. (Brazil's cultural manifestations are very rich.)
2. O governo deve investir mais em projetos culturais. (The government must invest more in cultural projects.)
3. Ele gosta de participar de festas culturais. (He likes to participate in cultural festivals.)
4. Estamos produzindo novos conteúdos culturais. (We are producing new cultural content.) Note: Brazilians typically use the gerund ("produzindo").
5. As diferenças culturais podem causar mal-entendidos. (Cultural differences can cause misunderstandings.)

Continental Portuguese Examples

1. As manifestações culturais de Portugal são muito ricas. (Portugal's cultural manifestations are very rich.)
2. O governo deve investir mais em projetos culturais. (The government must invest more in cultural projects.)
3. Ele gosta de participar em festas culturais. (He likes to participate in cultural festivals.) Note: Portuguese people typically use the preposition "em" with the verb "participar".
4. Estamos a produzir novos conteúdos culturais. (We are producing new cultural content.) Note: Portuguese people use the construction "a + infinitive" instead of the gerund.
5. As diferenças culturais podem causar mal-entendidos. (Cultural differences can cause misunderstandings.)