Suggestion; a mechanism to specify asset path for controller (or specified actions)

Good day!
Rails have layout method that allows you to specify a layout for controller or some it actions. So we can specify a template (HTML) for each action.

But not only HTML specifies page’s design (view) but CSS and JS, also. Asset, in Rails terms.

But can specify an asset for each action (by standard Rails’ mechanism, without dancing-with-bells :))? If not, I think it’s a good idea to have it - to have a possibillity to change the whole page’s design.

Thanx.

Couldn’t this be simply achieved by using a layout which uses different CSS files?

So

Layout1 loads CSS/desktop.css

Layout2 loads CSS/mobile.css

For example

What about images? Ok, I said: it’s possible. Is it possible with relax? For layouts - possible. But for assets?