cronstable

the full nonlinear cart–double-pendulum equations (Lagrangian, 2×2 mass matrix), integrated with RK4 at 240 Hz. energy drifts less than 10⁻⁵ relative over 20 s of free swing. there are no keyframes anywhere in this file.

at page load the dynamics are linearized numerically about the upright and a discrete Riccati equation is iterated (re-symmetrized — the naive recursion diverges on this stiff system) to get the gain row K. the controller rides out injected micro-gusts, so the idle logo is never perfectly still: watch the cart make little corrective darts.

when the dashboard loses its daemon the controller is unpowered: the pendulum crumples and the cart coasts. after 0.55 s the recovery controller wakes up.

the exact energy flow is dE/dt = −a·G, so the cart accelerates against G to pump the swing, saturating smoothly and recentering all the while. offline it targets 94% of upright energy — enough to keep striving, never enough to arrive — because an upright logo with no signal would be a lie.

near the top, a receding-horizon cross-entropy planner (0.96 s horizon, ~80 rollouts per frame, warm-started phase-correctly) threads the swing into the balance controller's narrow basin. a candidate catch is only committed after a full 2-second closed-loop rollout of the real dynamics says it will stand. patience escalates pump target and cart authority, so stubborn recoveries still land — median ~15 s, effectively certain by 90 s.

the letter is measured (canvas TextMetrics) and the sim scaled so the balanced pendulum — cart pivot on the baseline, tip at the stem's top — stands in for the glyph exactly; the controller's equilibrium x = 0 is the l's cell, so stability has an address in the word. the cart's track runs the full width of the wordmark — the end gates ARE the word's ends, so a hard recovery can ride out under "cronstab" and walk the standing letter back home. when it needs still more room, the right gate opens out toward mid-page — the physics bound lifts at once while the drawn gate flees just ahead of the cart, a phantom track filling in behind it — and once the letter stands at home again, gate and track glide back to the "e". it reads its colors from the active theme (--fg, --accent, --pending, --glow) and follows state.connected: standing as the letter while live, collapsed out of the word while reconnecting, healing the wordmark when the daemon returns. sweep your cursor through it and it feels the draft — speed, direction and where you graze it all matter; right-click knocks it clean over. with reduced motion it holds an honest still pose instead of animating. the printed l stays in the DOM (transparent) so copy/paste, screen readers and no-JS still read “cronstable”.