▸ Building the stellar-age axis: birth (nebula) → death (remnant)…
▸ Loading 10 phases: nebula → protostar → main sequence → red giant → …
▸ Calibrating lifetime ∝ mass (L ≈ M^3.5)
▸ Loading 5 mass tracks: 0.3 → 40 M☉
▸ Linking the Hertzsprung–Russell diagram · the star's life path
▸ Ready — Online. ✅