关桥后卡车自动改道的等距 3D 配送模拟器

Build an interactive 3D isometric delivery simulation of a small snowy town, running in the browser. Show houses, roads and two bridges in a pale blue and cream palette, with delivery trucks driving between a depot and addresses. Let the user close or reopen each bridge: trucks must reroute when one is closed, deliveries become unreachable when both are closed, and they recover when one reopens. Add a side panel with elapsed time, delivered, pending and unreachable counters, bridge toggles, a fleet speed control, a dispatch log and a delivery manifest dialog, plus pause, resume and reset buttons and a camera zoom view. Include an automated demo mode that plays the scenario. Write automated logic checks for routing and recovery. Done means all checks pass and the panel updates live.