HR diagram for the full sample. Evolutionary tracks for stars of masses 1.5, 1.7, 2.0, 2.4, 2.8, 3.6, and 5 M_⊙ are illustrated as gray curves. Black lines indicate selection boundaries for stars with M/M_⊙ ≥ 1.5 of solar metallicity, incorporating vertical temperature limits at 14 500 K and 7000 K. Color gradients denote the stellar density in each bin on a logarithmic scale. The spikes at the hot (T_eff ∼ 15 000 K) and cool (T_eff ∼ 6000 K) ends correspond to the temperature limits of the training models.