Sorry maybe that wasn’t the best example. It’s not really about separation of files. But how they connect.

In sql your code may be in a seperate file but your app code is still clearly calling the sql. The inlining vs not inlining is just abstraction. You could use a function, or a separate file or not, a different language or not.

But there is a clear single call chain at the points where that behaviour is being applied and a single definition.

With css that’s not necessarily true. There’s a bunch of different rules that may or may not apply.