Disc models in the equatorial plane corresponding to our best-fit parameters of the LB-1 system (see Table 3). The top and middle panels display the radial density and temperature stratification, respectively, and the azimuthal velocity component is shown in the bottom panel. The blue and red lines indicate the BH accretion disc (model PBH_SB) and the Be-star disc within the single-disc model (model PST_SBE01), respectively. For model PST_SBE02 (containing two discs), the Be-star disc is indicated by the green dotted line (partially overlapping with the red solid line from model PST_SBE01), and the stripped-star disc is indicated by the green solid line.