What a control does under the pointer and the keyboard. Every control answers the same way: hover strengthens, press shrinks, focus rings, disabled greys out.
Forced here; use the pointer and Tab to feel them. Focus shows for the keyboard only (focus-visible).
A fill one step stronger, or a stronger edge on raised controls. Only on devices that hover; touch skips it.
Buttons shrink to 96% while held. Not when they open a menu or popup (aria-haspopup).
One soft ring in the brand hue on controls and fields alike, outside the edge. Keyboard only.
Disabled fill and text, never opacity-50 (the slider is the exception). No pointer events.
On touch, every control under 44px grows an invisible 44px target (dashed). Checkbox, radio and switch extend with after:.