CSS media queries can't be done with inline styles, so that needs to probably switch to a class that can be defined in the global styles. (Alternatively, we could devise an extension to let you add <style> sections from templates, which might help since templates are being used here to add the inline styles.)
-1 We should limit where stylesheets can be added (although the idea in principle I am for). Otherwise we risk various pages introducing the same styles which will be awful to maintain (I'm seeing this problem with inline styles). I would prefer stylesheets per template/category that are applied to any page using them. This keeps the styles at a higher more reusable level.