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

Yes.

The word "boa" (the feminine form of the adjective "bom") is identical in meaning, grammar, and spelling in both Brazilian and Continental Portuguese. The only difference is pronunciation. Brazilian Portuguese tends to have more "open" and clearly articulated vowels, whereas Continental Portuguese often features "closed" or reduced vowels, particularly in unstressed syllables, which can make the word sound more neutralized or compressed.

Brazilian Portuguese

1. Essa ideia é muito boa. (This idea is very good.)
2. Boa sorte no seu trabalho! (Good luck with your work!)
3. A comida estava muito boa. (The food was very good.)
4. Ela é uma pessoa muito boa. (She is a very good person.)
5. Boa! Você conseguiu! (Nice! You did it!)

Continental Portuguese

1. Essa ideia é muito boa. (This idea is very good.)
2. Boa sorte no teu trabalho! (Good luck with your work!)
3. A comida estava muito boa. (The food was very good.)
4. Ela é uma pessoa muito boa. (She is a very good person.)
5. Boa! Conseguiste! (Nice! You did it!)