Internal profiles for a 12 M_⊙ star with f_c = 0.033, f_μ = 0.1, and f_ν = 1.0 and an initial velocity of 200 km s⁻¹ at 50% central hydrogen depletion. Left: Diffusion coefficients for chemical mixing and the helium abundance (left y-axis) and abundances of both boron isotopes, carbon, and nitrogen (right y-axis). The solid lines indicate diffusion coefficients, while the dashed lines indicate chemical abundances. Helium mass fraction Y is multiplied by 20 for better visibility. Right: Diffusion coefficients for angular momentum transport (solid lines) and angular velocity (dashed line).