The nav dock rides MUSIC_DOCK_HEIGHT higher while the music dock is up, but the hide threshold was still measured from the bottom — so hovering the raised dock read as past HIDE_THRESHOLD and it slid away under the cursor. Lift hideAt (and the magnify gate) by MUSIC_DOCK_HEIGHT; the reveal trigger stays at the edge. Also read musicDockPresent via a ref so the once-registered mousemove handler reacts to music starting/stopping. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>