export css file to be available through a url

I have the following scenario.

Two independent node projects need to have the same css colouring. My idea is that I have a custom.css in my public folder of my node project, and another node project would be able to consum this file over a link. For example, if my node project runs on localhost:3000, my idea is that the css file would be available by localhost:3000/custom.css.

Does anybody has an idea how to do that?

I am looking for a way to implement such a link to export the css.

Thanks in advance