Doesn't include .css, Mime type error?

Question

css

Error - Refused to apply style from ' localhost:3000/css/index.css ' because its MIME type ('text/html') is not a supported stylesheet MIME type, and strict MIME checking is enabled.
File structure:

-html
--main.html//link rel="stylesheet" type="text/css" href="../css/main.css"
-css 
--main.css

I collect through gulp'e I use normalize.scss, I read that this may be due to comments at the beginning of .css, but I think this is nonsense.
When I make sure that .ccs and .html are in the same folder, and I write the path directly (href='main.css'), it works, but I don't want to use such a structure, help please))

Answer 1

I did it, on the advice of a friend, I simply transferred .html to one directory above, and registered the path /css/main.css and it all worked.

Answer 2

Stas Schmidt
Hello!
I've been struggling with the same problem for an hour, but all in vain. Need help plz.