HTML Opus #01
7.9
Evaluation
7.9 avg
8.5 physics accuracy
8.8 design quality
8.2 animation quality
5.5 slider ux
8.5 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 "Luft" (air) is at the top and "Wasser" (water) at the bottom, but slider min=0 maps to air and slider value increases downward on screen yet the crown moves into water as value increases, which is technically correct in behavior but the CSS `transform: rotate(-90deg)` on a standard horizontal slider means dragging right (increasing value) visually moves the thumb downward toward "Wasser," making direction consistent — however a proper `writing-mode: vertical-lr` vertical range is not used and cross-browser reliability is questionable; all other features (splash, ripples, Eureka overlay with confetti, live data panels, comparison bars, water rise) are well-implemented with solid physics (gold 19.32 g/cm³, gilded 11.0 g/cm³, same 1000 g mass).

13,055 output tokens · claude-opus-4-6 · end_turn

Slider direction is inverted — the label "Luft" (air) is at the top and "Wasser" (water) at the bottom, but slider min=0 maps to air and slider value increases downward on screen yet the crown moves into water as value increases, which is technically correct in behavior but the CSS `transform: rotate(-90deg)` on a standard horizontal slider means dragging right (increasing value) visually moves the thumb downward toward "Wasser," making direction consistent — however a proper `writing-mode: vertical-lr` vertical range is not used and cross-browser reliability is questionable; all other features (splash, ripples, Eureka overlay with confetti, live data panels, comparison bars, water rise) are well-implemented with solid physics (gold 19.32 g/cm³, gilded 11.0 g/cm³, same 1000 g mass).