It's a soft adjective, those end with -í in nominative regardless of gender. Check the tips and notes provided (click on the light bulb icon, web only at the moment).
when i looked at what strange meant at the bottom and it said cizi so i decided to type it down but it said i was wrong
The suggestions aren't tailored for each and every sentence, they are general. In this case, "cizí" is incorrect. To explain the difference: CIZÍ = FOREIGN, ZVLÁŠTNÍ = WEIRD