✓ 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 → crowns in air is correct, but the vertical slider CSS uses writing-mode/rtl such that the physical top of the slider corresponds to 100/water rather than 0/air); physics values are accurate (gold 19.3, gilded 8.5, same 300 g mass), ASCII rendering is creative and complete, but the shimmer-driven re-render loop causes slider jitter and the crown ASCII art is too narrow relative to the tank width making the visual comparison of displaced water subtle.
Slider direction is inverted (value=0 → crowns in air is correct, but the vertical slider CSS uses writing-mode/rtl such that the physical top of the slider corresponds to 100/water rather than 0/air); physics values are accurate (gold 19.3, gilded 8.5, same 300 g mass), ASCII rendering is creative and complete, but the shimmer-driven re-render loop causes slider jitter and the crown ASCII art is too narrow relative to the tank width making the visual comparison of displaced water subtle.