HTML Opus #12
7.9
Evaluation
7.9 avg
8.5 physics accuracy
8.5 design quality
8 animation quality
5.5 slider ux
9 completeness
7.8 overall
Two crowns Same mass, different density Vertical slider Slider works Slider controls crowns Slider direction correct Full slider range Fall animation Water displacement Rising water level Splash effects Physics correct Live mass value Live volume value Live density value Live displaced water Gilded displaces more Heureka animation No external deps Light bg / dark text Self-contained HTML

Slider direction is inverted — the label layout says "Luft" (air) at top and "Wasser" (water) at bottom, but the vertical-lr + direction:rtl CSS transform causes the thumb to start at the bottom (water) when value=0 and rise to air at value=100, contradicting the intended and labeled mapping; every other feature is solidly implemented with good physics, rich visuals, and a full Heureka payoff.

10,580 output tokens · claude-opus-4-6 · end_turn

Slider direction is inverted — the label layout says "Luft" (air) at top and "Wasser" (water) at bottom, but the vertical-lr + direction:rtl CSS transform causes the thumb to start at the bottom (water) when value=0 and rise to air at value=100, contradicting the intended and labeled mapping; every other feature is solidly implemented with good physics, rich visuals, and a full Heureka payoff.