✓ 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 at top means air, but CSS uses writing-mode vertical-lr with direction:rtl, making the physical top of the slider the maximum, so dragging down sends the crown INTO water — but semantically min=0/max=100 with the thumb starting at top meaning 0% immersion is actually correct directionality; however the visual track gradient goes light-to-dark top-to-bottom suggesting "down = deeper" which is correct, yet the label/UX feel is ambiguous — main flaw is the crown submersion mapping uses a simplified linear proxy rather than true geometric displacement, and the water-rise formula is a rough visual estimate rather than calculated from tank cross-section.
11,066 output tokens · claude-opus-4-6 · end_turn
Slider direction is inverted (value=0 at top means air, but CSS uses writing-mode vertical-lr with direction:rtl, making the physical top of the slider the maximum, so dragging down sends the crown INTO water — but semantically min=0/max=100 with the thumb starting at top meaning 0% immersion is actually correct directionality; however the visual track gradient goes light-to-dark top-to-bottom suggesting "down = deeper" which is correct, yet the label/UX feel is ambiguous — main flaw is the crown submersion mapping uses a simplified linear proxy rather than true geometric displacement, and the water-rise formula is a rough visual estimate rather than calculated from tank cross-section.