Goodwin operon — dx/dt=a/(1+zⁿ)−x, dy/dt=x−y, dz/dt=y−z. Classic a=15 n=12 (equal rates). Dual a+n sliders; b=α=β=γ=δ fixed 1. Display embed (x,y,z). Distinct from bell.html, oregonator.html, willamowski.html, hindmarsh-rose.html, lorenz.html. Bulk centroid ≈ (1.4067, 1.4076, 1.4075). RK4 genetic fold. Gold low-alpha trail, cap 650. RM = settled silhouette, no animate-on.