I assume you are going to add a copyright notice as a comment e.g. /* some content */, if that is the case, it can go anywhere and it wont affect anything. It is a comment - here is some info https://css-tricks.com/snippets/css/comments-in-css/

As for copyright notices, firstly, are you going to go to the effort and expense of attempting to enforce your copyright? If not, why bother?

To cover your static/dynamic dilemma does something like (c) Copyright 2013 - 2017 do the job? The current year can even be dynamic using date('Y').

I assume you are going to add a copyright notice as a comment e.g. /* some content */, if that is the case, it can go anywhere and it wont affect anything. It is simply text that displays a message to someone who reads the source, but it isn't processed.

As for page copyright notices - which assume is what you mean by displayed in the page, firstly, are you going to go to the effort and expense of attempting to enforce your copyright? If not, why bother?

To cover your static/dynamic dilemma does something like (c) Copyright 2013 - 2017 do the job? The current year can even be dynamic using date('Y').