Fullscreen piano redesign:
- 1 octave with 7 large white keys filling the entire screen
- Gradient-lit keys with cyan press highlight
- Octave navigation buttons (◀ ▶) to shift up/down
- Note labels on each key (C4, D4, etc.)
- Black keys proportionally sized at 58% height
- touch-action: none to prevent any browser interference
Block native browser zoom:
- viewport meta: maximum-scale=1.0, user-scalable=no
- html touch-action: manipulation (prevents double-tap zoom on Safari)
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>