meaning - How to interpret this kind of sentence?

I have a question related to an example sentence below. I always have slight doubt in interpreting sentences which have this kind of clauses being connected.

Consider this sentence:

The book covers the fundamental building blocks of digital design across several levels of abstraction, from CMOS gates to hardware design languages.

Here, to which part of the first clause in the sentence is the second clause — "from CMOS gates to hardware design languages" — related?
I mean whether CMOS gates and hardware design languages are

• fundamental building blocks of digital design, or


• several levels of abstraction.