Vertical slice through the 3D RHD simulation domain for two selected main-sequence stars (see Table 2) with solar metallicity, log g = 4.5, and T_eff = 5500 and 6500 K. Note the differences in the vertical sizes of the boxes. Coloured contours corresponds to iso-temperature (left) and iso-log τ_ross surfaces (right). To the left of each panel, the geometric extension and respective profile of the corresponding 1D HE MARCS model, computed using the same stellar parameters (T_eff, log g, [Fe/H], and micro-turbulence of 1 km s⁻¹) is shown.