Radial profiles of a 3 M_⊙ star halfway through the main sequence with a central hydrogen content X_c = 0.4. Top panels: temperature gradients. Middle panels: structure (solid) and composition (dashed) components of the Brunt−Väisälä profile, as well as the shape of the mixing profiles, divided in convective core (grey), near-core mixing (blue), and diffusive mixing in the outer radiative envelope (green). Bottom panels: mode inertia of two g-modes with different radial orders. (a) Near-core region with radiative temperature gradient. (b) Near-core region with temperature gradient according to Péclet number.