responsive interactions not working with custom post types and taxonomies

I want the sidebar to show up across my site and have selected that option on the theme settings. When viewing the news page (which uses the archive.php template), everything is fine. However, if I copy the template to use it for the library page (a custom post type), the sidebar is shoved to the bottom.
I can see that the widths of the sidebar and main divs are no longer being called and can define them manually in my child theme style.css file, but then run into the problem that they are fixed this way, even when viewed on a phone.
How do I untangle this? Is there some place I can add other post types and taxonomies to wherever the code is that handles the responsive divs?