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

Yes

The word "tema" is identical in meaning, spelling, and grammar in both Brazilian and Continental Portuguese. The only difference lies in pronunciation. In Brazilian Portuguese, the vowels are generally more open and the "a" at the end of the word is more distinct and vocalized. In Continental Portuguese, unstressed or final vowels are often more closed or reduced, leading to a shorter, more clipped sound.

Brazilian Portuguese Examples:

1. O tema da redação é bem difícil. (The topic of the essay is very difficult.)
2. A gente precisa escolher um tema para a party. (We need to choose a theme for the party.)
3. Esse tema é muito polêmico. (This topic is very controversial.)
4. Qual é o tema do seu projeto? (What is the theme of your project?)
5. O tema da palestra foi muito legal. (The theme of the lecture was very cool.)

Continental Portuguese Examples:

1. O tema da redação é bastante difícil. (The topic of the essay is quite difficult.)
2. Temos de escolher um tema para a festa. (We have to choose a theme for the party.)
3. Este assunto é muito polémico. (This subject is very controversial.)
4. Qual é o tema do teu projeto? (What is the theme of your project?)
5. O tema da palestra foi muito fixe. (The theme of the lecture was very cool.)