Plugin with sidebar: how to modify small-width, medium-width, large-width?

[mikechristopher]

you do know there are other sidebar plugins out there dont you - for example

Discourse Sidebar Blocks

This plugin is now deprecated. Please use the Right Sidebar Blocks theme component instead. This plugin shows a list of blocks as a sidebar on all discovery list pages (latest, new, unread, categories but not on the single topic page). The available blocks at this point (Oct. 12 2016) are the following: multiple category posts (6 items max per category) latest replies (5 items) a custom html block Blocks can be ordered in the plugin settings. Speaking of which, there are these se…

Might be worth looking at how they do it - if you want to create your own that is.