✓ 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 (min=0/top means crowns in air, but HTML vertical range sliders typically render with max at top, and the auto-drop auto-increments from 0→100 moving crowns down, so the physical mapping is correct in code but the visual slider thumb moves upward to submerge, which is counter-intuitive); crown rendering is a rough circle-with-dots approximation rather than a recognizable crown shape, and the water-rise calculation uses canvas pixel width as container area producing physically nonsensical cm values for water level.
Slider direction is inverted (min=0/top means crowns in air, but HTML vertical range sliders typically render with max at top, and the auto-drop auto-increments from 0→100 moving crowns down, so the physical mapping is correct in code but the visual slider thumb moves upward to submerge, which is counter-intuitive); crown rendering is a rough circle-with-dots approximation rather than a recognizable crown shape, and the water-rise calculation uses canvas pixel width as container area producing physically nonsensical cm values for water level.