Is there any standard place and way to define a css file and reference it in some of the pages of a subsite?
The following code works, but having an absolute path and an arbitrary location doesn't seems to be a good solution (specially when we are dealing with hundreds of topics.
<link rel="stylesheet" type="text/css" href="PATH_TO_FILE/mystyle.css">
Attaching your CSS file at any page and referencing it by appending /pub/%WEB%/Webhome/ to the path works. Maybe not a standard solution, but still works.