Vertical (top panels) and radial (bottom panels) net (inflow minus outflow) gas flow rates through an inner (0 < R (kpc) < 5), central (5 < R (kpc) < 16), and outer (16 < R (kpc) < 26) annular rings for cold (T (K) < 5 × 10³), warm (5 × 10³ < T (K) < 10⁵, middle), and hot (T (K) > 10⁵) gas. Positive net fluxes correspond to inflow (i.e. gas entering the corresponding ring), while negative values indicate gas outflow. The vertical lines in the panels indicate the lookback times (3.6, 7.7 and 10.9 Gyr ago) that separate the formation and evolution of the three disc phases identified in Romeo.