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

Yes

The word "detalhe" is identical in meaning, spelling, and grammar in both Brazilian and Continental Portuguese. The only difference is in pronunciation. In Brazilian Portuguese, the vowels are typically more open and clearly articulated. In Continental Portuguese, unstressed vowels (such as the "e" in the first syllable) undergo "vowel reduction," meaning they are pronounced much more softly or even swallowed, making the word sound more clipped or "closed" to a Brazilian ear.

Brazilian Portuguese Examples

1. Preste atenção em cada detalhe. (Pay attention to every detail.)
2. O projeto está perfeito, só falta um pequeno detalhe. (The project is perfect, only one small detail is missing.)
3. Ele explicou tudo com muitos detalhes. (He explained everything with many details.)
4. Eu não vi esse detalhe na foto. (I didn't see that detail in the photo.)
5. Cada detalhe é importante para o sucesso do plano. (Every detail is important for the success of the plan.)

Continental Portuguese Examples

1. Presta atenção a cada detalhe. (Pay attention to every detail.)
2. O projeto está impecável, só falta um pequeno detalhe. (The project is impeccable, only one small detail is missing.)
3. Ele explicou tudo com muito detalhe. (He explained everything in great detail.)
4. Não vi esse detalhe na fotografia. (I didn't see that detail in the photograph.)
5. Esqueci-me de um detalhe importante no contrato. (I forgot an important detail in the contract.)