City building orders now keep their production-queue slot but open in a materials phase: the order reserves the market value of its steel and high-tech, buys from the nation's own stores and reachable suppliers once a day, and only joins a construction line once the bill is settled, so a city with no supplier simply waits. The queue, the city panel and the quick view show the gathering progress instead of a stalled bar.
Buildings and tile improvements now take a tenth of the old time; unit training is untouched. Any material money left over is returned when the work completes.