Virus Entry: Receptor Binding & Membrane Fusion (2D)

This 2D companion drives the same spike-receptor entry mechanism as the 3D version through a plain canvas view built for reading the biophysics rather than orbiting a scene: every binding contact is resolved by the Hill-Langmuir occupancy equation from real receptor-binding pharmacology, a live dose-response plot shows the empirical Monte-Carlo success rate converge on that analytic curve as trials accumulate, and — for the endocytosis pathway — a genuine exponential acidification kinetic drives the endosomal pH down until it crosses the real hemagglutinin-class fusion trigger, all exposed through sliders instead of implied by an orbiting scene.