[kazinator]

The spacing of the white keys is correct in the sense that they are of equal width. However, the black keys on a real keyboard are not centered between adjacent white keys (except for the G# between G and A).

The placement so that the two groups of black keys, C#-D# and F#-G#-A#, are a little bit wider than the naive on-center placement, as if they were repelled from each other.

The thin parts of the white keys that are between the black keys are evenly spaced with the black keys: i.e. all 12 semitones are equally spaced at the back. The rear ends of the keys directly link to the striking mechanism, which lines up with evenly-spaced string courses.