proposal: @require, a "dependent @import", if the required CSS file fails to load, all the declarations in the container file also fail.

[Zhang-Junzhi]

CSS files can be strongly dependent on other CSS files, it wouldn't make senses to still render based on the declarations if the CSS file they depend on fails to load.

Users would rather even see a completely unstyled document, than see a document which is "half" rendered in a mess.

So sometimes CSS files need to be made "atomic" — either they all succeed, or they all fail.

So I'd like to see something like @require, a "dependent @import" available.