Arthur Costa

Why this design colophon

Concept. I built offline-first sync that converges without a central source of truth, so my profile is two replicas, at work (teal) and on my own time (ochre), edited apart and merged without a coordinator.

Information architecture. The first screen is the partition: what both replicas agree on spans the dashed line, each half of my one-liner and its results sits on its side, and the portrait heals across it. Below come the two op logs, each record showing its outcome and opening in place; the heal, drawn as both logs converging on one axis; the merged state as a join on id; the tombstone rule from AC-009; and one section for everything both replicas already agree on.

Portrait. The header portrait is your version vector: cells written on A fill in as you read A, cells written on B as you read B, and the heal fills in what you skipped. The page ends on the converged photo.

Typography. Sono carries headings, labels and counters because its MONO axis is the merge: a dashed partition runs through my name, Arthur in teal and Costa in ochre; when the replicas converge it closes, the letters turn ink and fully monospaced, and headings are proportional above the heal and half-monospaced below it. Every sentence is set in Literata, a reading face drawn for the same book on many devices.

Colour and motion. Teal and ochre are a complement and a neighbour of my skin tone, always paired with a label. The two new animations, the logs converging and the tombstones, are merge rules I have used; the portrait plays once and holds.

Accessibility. “Pause animation” stops everything and reads “Resume animation” while paused; reduced motion shows every end state; each figure has a written equivalent; every control is at least 44 px.