Window Grab Bar

Window grab bar, a slim matte pill 0.12 x 0.012 m, 0.004 m thick (length 0.08-0.2 m, ends never scale), floating under an XR window; the accent glows along it. Hover widens it slightly and glows; pressed settles it; selected stays wide and lit.

风格：low-poly, flat-shaded vertex colors, no textures, 3 materials: the shared opaque one plus a distinct surface (glass, water or chrome), which stays its own mesh through mergeAssets rather than merging into the rest; shares palette and scale with its kit