Finished TIC TAC TOE

I finally finished my tic-tac-toe. The hardest part of the project is the minimax algorithm.
Please comment and give feedback.


As far as I tested, everything works fine.
Design is looking good.

There is no responsive layout.
Is there a way to control, which player is starting the game?

The game chooses the player to go first randomly. And no, there is no responsive layout. I figured, I’ll do that later.