Tailwind CSS not working with Angular

I can not get Tailwind CSS working with Angular. I create a new project and select the Angular template. Then I follow the official Tailwind CSS installation instructions for Angular here
But it is just not working. Can someone confirm this? Or is there something I am doing wrong?
I already asked Gemini AI and sent him all contents of the relevant files and he confirmed, that everything looks right.
Can someone help me please?

By not working I mean, no matter which style classes I apply, it doesn’t change anything…