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

Yes

The word "fantásticos" is identical in spelling, grammar, and meaning in both Brazilian and Continental Portuguese. The only difference is in pronunciation:

• Brazilian Portuguese: The vowels are generally more open and clearly articulated. The final "s" is typically pronounced as a sharp [s] (though in certain regions like Rio de Janeiro, it may take a [ʃ] "sh" sound).
• Continental Portuguese: The vowels are much more closed and often "reduced" or swallowed (making the word sound shorter). The final "s" is almost always pronounced as [ʃ] (a "sh" sound).

Brazilian Portuguese Examples

1. Os novos professores são fantásticos. (The new teachers are fantastic.)
2. Estes filmes são fantásticos. (These movies are fantastic.)
3. Eles fizeram trabalhos fantásticos. (They did fantastic work.)
4. Os sabores destes pratos são fantásticos. (The flavors of these dishes are fantastic.)
5. Tivemos dias fantásticos na praia. (We had fantastic days at the beach.)

Continental Portuguese Examples

1. Os novos professores são espetaculares. (The new teachers are spectacular.)
2. Estes filmes são fixes. (These movies are cool/great.)
3. Eles fizeram trabalhos espetaculares. (They did spectacular work.)
4. Os sabores destes pratos são maravilhosos. (The flavors of these dishes are wonderful.)
5. Tivemos dias espetaculares na praia. (We had spectacular days at the beach.)