CUSTOM CSS in article block

Hi
How does "custom css" work in an article block?
I needed to change the color of one link to a different color than the other, and entered the corresponding css code in the "custom css" tab. but it didn't work. Only entering this code in the template "Template creator CK" worked correctly.

Hi
in some areas the custom css option is not clear, so you shall not use it
it is part of the general interface, so I can difficultly choose where to use it or not
if you want to target something in your articles, you shall use the custom css from Parameters and write the rule
CEd

I entered the code in the main page template, I think this is the most understandable for me and I know that it will work 100%