* Shrink button icons to 16px at both sizes The medium button provided its nested icons and spinner a 24px icon size, which read as oversized against the 40px control and left the icon larger than the pending spinner IconButton already drew at 16px. Both button sizes now take a 16px icon, so the size-to-icon lookup table collapses to a single constant. * Show the flat icon size in the button docs examples The size example was label-only, so nothing in the docs showed that the icon holds at 16px while the control grows. Give both sizes a start icon. Drop the explicit aria-hidden from the icons example: Icon already defaults it to true when no title is set, so the prop taught readers a step they can skip.