# Mix Math

Mix Math is an offline-capable addition game for young learners.

## Privacy and browser storage

Mix Math has no accounts, cookies, sessions, telemetry, database, or server-side game-state storage. It does not send profiles, gameplay, or progress to the server. The server only delivers the application and static assets.

The browser stores the following durable data in `localStorage` under `mix-math-data-v1`:

- whether initial setup is complete;
- each local profile's generated ID, first name, and selected animal;
- total plays, answers, correct answers, and per-game answer/correct counts.

The active screen and profile, current questions and answers, wave score, feedback, PIN entry, and calculator choices exist only in browser memory and reset when the page reloads. The service worker's Cache Storage contains only the application shell and static assets so the game can load offline. The production build publishes this worker as `/mixmath-service-worker.js`; it must not use `/service-worker.js`, which Amp Sites reserves.

Removing a profile in grown-up mode deletes that profile and its progress from localStorage. Clearing this site's browser data removes all profiles, progress, and offline assets. Because data stays in one browser profile, it does not sync between browsers or devices and cannot be recovered from the server.

Data from other browser storage keys is not imported. Previous releases never supported downloading server snapshots, so a browser with no local copy cannot recover one. Operators upgrading an existing deployment should delete any historical `.data/sync` files created by versions that offered server sync; current code neither reads nor creates them.