✓ 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 (value=0 → crown in air is correct, but HTML range with `writing-mode: bt-lr` on a vertical slider maps visually upward to higher values, meaning dragging down increases depth — this is actually correct directionally, but the instructional label says "Slider nach unten ziehen" while default value=0 starts crowns in air, so direction is consistent); however, mass/volume/density displays are static (not live/reactive to slider), and there is no smooth fall animation — the crown teleports rather than animating.
Slider direction is inverted (value=0 → crown in air is correct, but HTML range with `writing-mode: bt-lr` on a vertical slider maps visually upward to higher values, meaning dragging down increases depth — this is actually correct directionally, but the instructional label says "Slider nach unten ziehen" while default value=0 starts crowns in air, so direction is consistent); however, mass/volume/density displays are static (not live/reactive to slider), and there is no smooth fall animation — the crown teleports rather than animating.