Is following other people of authority shirk

Hi I've read that following ruler who follows man made laws here https://islamqa.info/en/974 In this link ========== Is shirk but if a school has free mixing and music classes etc and administration requires students to wear school uniform which isn't covering well but the school teachers and administrators and owners are probably ignorant about these things and if they allow democracy are they tughut and is following their rules and wearing their uniforms kufr or shirk?