Was `top: calc(50% + 4px)` which left the button 4px below the
true vertical center of the input — visibly misaligned. Dropped
the +4 offset so the toggle anchors at top:50% / translateY(-50%)
and tracks the input's center.
Also removed the redundant base rule's position:relative + top:2px
nudge — it was being overridden by the more-specific
.email-field .email-cc-toggle absolute positioning anyway.
81a9a1fed3