Surface B · The building cursor

The mark gains a side, then resolves

_ → + → △ → □ → _. The cursor builds up through the shapes while thinking, then collapses back to the waiting underscore. Watch the two side by side — the geometric build is your extension.

1 · Thinking cursor — simple morph vs geometric build

C1 · Morph

_ → caret → dot → _. Three forms, abstract.

C2 · Geometric build (rec.)

One line → two (plus) → three (triangle) → four (square) → back. Counts up, then settles.

_  →  +  →  △  →  □  →  _

2 · Reply button — substantial outline, no fill

Transparent, but a confident border + bold white so it reads finished, not disabled. Tap it — red on contact (action), then fades.

Does the geometric build feel right (and at this tempo — 4s full cycle)? And is the outline button finished now? If yes, B locks — the building cursor becomes Mallory’s thinking signature — and we move to C · settings & native consistency.