山区步道公厕：无水系统与运输限制

Design a toilet on a mountain hiking trail where there is no water, no power and no vehicle access. Show a small structure built from materials that can be carried in by hand or dropped by helicopter — a light timber frame with prefabricated panels, bolted rather than welded, sitting on adjustable pad footings that touch the slope at only six points so the ground is barely disturbed. Detail the system as waterless: a composting or bagging arrangement with a visible ventilation stack rising well above the roof, painted black to drive airflow, and a clearly labelled access hatch at the rear for removal. Show a hand-sanitiser dispenser rather than a basin, and a solar panel on the roof powering a small fan and a light. Detail the exterior in untreated local timber weathering to grey, with a simple metal roof and a deep overhang. Show the setting as an exposed alpine trail with rock, low shrub and a long view. Include a sign explaining the system and asking users to carry out waste. Photorealistic, rugged, weathered timber against rock, three-quarter view.