The card-wide `border-box` reached `.fieldMirror`, so the growth cap counted
text plus padding. The inline variant carries none and landed on the declared
line count, while the optionless variant's 16px inset spent two thirds of a
line and delivered its last one as an 8px sliver. The e2e measured only the
inline shape, so nothing caught the drift.
The mirror now takes `box-sizing: content-box`, which states the cap in the
units it is written in, and the cap moves to six lines. The e2e asserts whole
text lines rather than a box height, and covers the optionless shape — asked
straight through the user-questions seam, since a layout metric needs no model
round — including that the reserved empty field is fully covered by its own
control.
A question that carried options collected its free-text answer in a
single-line input: a long sentence scrolled sideways inside one line and
Shift+Enter was inert, so an answer with structure could not be typed.
The optionless question already used a textarea, but a fixed 64-140px box
that never followed the draft.
Both shapes now answer into one AnswerField: a `textarea rows=1` sharing a
grid cell with a hidden mirror that renders the draft plus a trailing
newline and so owns the height. Soft wraps are invisible to a '\n' count,
so the mirror is what grows the box; growth stops at eight lines and the
textarea scrolls from there, keeping the choices the answer belongs to in
view. Enter still continues and submits, Shift+Enter breaks the line, and
the IME guard is unchanged.
Yichen Jiang