The Basic theme provides a simple yet highly themable structure. It's leveraging the bulk of our custom elements specifically geared toward HAXcms state encapsulation
The theme elements in HAXcms can completely encapsulate state. So the menu on the left of this design (as one example) is called `< site - children - block >
That means if you used it in your theme, you could easily just style it and never have to think about state management / what's active. This approach is in all our themes at some level, the most pervasive of which is the next and previous buttons which are `< site - menu - button type="next >` in their format.