Day 2

I am leaning more towards not stairs, but entirely ramps.
Big, wide ramps. This would (unfortunately, though necessary[?] for car transportation between levels. There would be overhangs/roofs on these ramps, made of solar panels, and gates so people don't fall out, but there would be space between the railings and roof, for a view. The roof would also have a 'V' shape, so rain would collect and flow to ... something.
Elevators would be fit in as many places as possible, even from a store on level 2 to an area on level 3. They could be powered by electricity, or we could go really old school and have it pedal powered, using mutliple people. It would have a safety lock so that it couldn't go down if the pedalling stopped; but we'd have to have multiple elevators.
Ziplines would be on platform on the same level. It could be a fairly intricate dealeo.
Firepoles would be simple, green, and ubiquitous.
My plan for the ramps would be: there would be a bunch of them. They would link all levels. There would be 'off ramps' to the second level. It would sort of have the basis of a bridge, with side areas for walkers (they would be wider than most), and with the centre reserved for bikes, mopeds, cars, and segways.

Fin.