combine css files with html

Question

Hello guys.
I have a problem with css files
I've tryed to combine a html file with a css file.
i've linked it in the head selection.
but nothing happen in the output.
Is it possible that pseudo classes are not available in internet explorer?

Answer 1

You can check for browser support here:
https://caniuse.com/#search=pseudo

Answer 2

can you type your codes into code playground and share here for examination?