Where you apply custom CSS will determine where it is used. For example, if you add CSS to a theme’s style.css file or to a custom CSS plugin designed to override theme styles, none of that CSS will ever touch the admin. That requires a completely different approach.
So if you are asking if you can add custom CSS to your theme or custom CSS plugin and NOT have it affect the WordPress admin dashboard, the answer is yes, your CSS will only apply to the front-end of the site.
If that is not what you are asking, please let me know what you are trying to do in more detail.
Hi and thanks for the reply.
I just want to add custom CSS that will take effect only on admin’s dashboard and not on other users(eg editors/authors) or the opposite.