This 2D companion simulator renders the same integer-quantum-Hall point-contact physics as a genuine semiclassical picture: each chiral edge channel is drawn as a chain of exact semicircular cyclotron arcs skipping along the sample boundary, rather than a flattened 3D scene. A pair of split gates narrows a quantum point contact in the middle of the bar; as the gate voltage increases, channels are pinched off one by one starting with the innermost, exactly reproducing the Landauer-Büttiker conductance staircase G = N·e²/h. A second, fully 2D-native panel sweeps the same transmission rule across every gate voltage to plot the conductance-vs-gate-voltage staircase directly — a parameter-space diagram with no analogue in the 3D real-space view — and marks your live operating point on it as you move the slider.