About unused CSS and hidden Elements

[BloodlineL]

When the selector contains :has or :not, even if no elements are matched, it will not be removed.
Another question is why some hidden elements are nested instead of just saving the top level.

[gildas-lormeau]

Thank you. In fact, for this option, the aim is not really for SingleFile to be 100% efficient but to remove most of hidden elements without breaking the layout. I agree that optimizations would be desirable though.