T324102, which concerns a legal requirement, will likely entail converting PhonosButton to an extension of (or wrapping it in) ButtonGroupWidget and thus a CSS overhaul.

Design QA:

Overall it looks really great! Thanks for adding the progress bar. We only found some minor visual misalignments with the proposed design that I am listing down below:

Analysis	Current implementation	Proposed design
Missing padding around the phonos button
Border looks a bit thick visually. If 2px is being used in the code, can we try with 1px please?

@nayoub please feel free to add anything else I might have missed out.