.picker-count inherited the generic button's 12px/16px padding, which
left ~16px of content width per grid cell — enough for a single digit
but not the two-character "-1".."-5" remove labels added in #72,
which overflowed into the neighbouring cell and got visually clipped
by its opaque background. Tightened to horizontal-only padding (12px
4px), leaving vertical spacing/centering untouched.
91d14b33bb