The demo city is a rendering stress test — an arterial street grid with zones laid out by distance from the centre. There is no simulation behind it yet; that is Phase 2.

Applies to the app chrome. The city's own day/night cycle runs on the in-game clock, independent of this.

Autosaves to this device (IndexedDB). Cloud sync across devices is a later phase.

MetroBuild runs entirely in the browser. Nothing is uploaded and no external service is contacted, so there is no API quota to watch.

Phase 1 draws and lights a city. Zone demand, land value, traffic and growth arrive in Phase 2 — right now a zoned lot gets a deterministic placeholder building so there is a skyline to render.