If I add a link to an external resource as a module item, leaving "load in new tab" unchecked, the resource will render in an iframe in a canvas page. That iframe is way more responsive than anything I seem to be able to kludge together with the limited allowed CSS.
Is there a class/etc. that can be applied to iframes to make them behave more responsively in, like, Pages and Discussions?
I've inspected the code for one of those external resource pages, but it's such a rat's nest that I haven't been able to find anything useful.