Tailwind classes stopped working (only previously used and customly added classes work)

for some reason my tailwind doesn't work anymore. I was able to use any classes and they were being added to style.css with: "npx tailwindcss -i tailwind.css -o ./css/style.css --watch". But today it just stopped working, I can't apply even the most default class like text-red-400. I can only use classes that I have previously already used AND ones that I have customly added.