Moon Jump

Build "Moon Jump" — a polished mobile-first portrait web app for the Eazo community.

CONCEPT
A tiny astronaut stands on a launchpad. HOLD to crouch and charge the jump — release to leap. The same charged jump replays across worlds you swipe between: on Earth a modest hop, on the Moon a six-story float with hang-time to spare, on Jupiter a pathetic crouch-twitch, on Phobos you simply… leave. Each world renders its own sky, horizon curvature, and dust physics; the fun is feeling identical effort produce absurdly different fates.

RULES & STATES
- Hold-to-charge with a compressing spring animation; jump physics use real relative surface gravities from embedded constants.
- 8 worlds (Earth, Moon, Mars, Jupiter, Phobos, Pluto, a neutron star with a safety warning, and "your home planet: bed"); swipe to switch, jump replays with the same charge.
- Altitude tape measures each jump against landmarks (giraffe, house, the ISS eventually on Phobos).
- Result card: "Jump License" — your best jump per world drawn as a comparative arc chart with hang-times, stamped by the Interplanetary Athletics Board.

OPENING
No cover page: the app opens straight into the live interactive scene, playable on first paint. A floating title chip and one animated gesture hint dissolve on the first touch. Keep gentle ambient motion (drift, breathing, particles) at all times so the scene never looks frozen.

GLOBAL REQUIREMENTS
- Language: ship a lightweight built-in i18n layer with exactly two locales, English (en) and Chinese (zh). The app ALWAYS opens in English — never auto-detect or follow the system/browser language. Provide one small, comfortably tappable EN / 中文 toggle placed top-right, about 56px down from the top edge, clear of the device status bar. Chinese appears only after the user actively switches. All share output stays English regardless of locale. Never mix two languages on one screen.
- Fully self-contained: absolutely no external APIs of any kind — no AI calls, no third-party data, media or font services, no remote backend, no login. Embed all data and content in the app code.
- Real Share to the Eazo Community: on the result screen add a real Share button. Compose the result card as an image on a canvas and share it through the Eazo SDK community share (share.compose with the image attachment plus a short English text). Read the resolved { accepted } value: only when accepted is true may the button say "Sent to Eazo"; when accepted is false the button must read "Open in the Eazo app to share"; on error keep the original button. Never claim the post was shared on the plain web. Keep a Replay button next to Share.
- Mobile-first portrait, touch-only, no hover dependence. The app root must follow the host container height (position: fixed; inset: 0; height: 100%) — never 100dvh or 100svh. Size any canvas from its PARENT element using a ResizeObserver (run the fit once on mount), and convert every touch event through getBoundingClientRect() read at event time — never cache the rect and never use window.innerWidth/innerHeight for canvas sizing.
- Safe areas: keep all top UI at least 56px from the top edge. Keep every core interactive control (start button, submit, share, play controls) fully above the bottom 88px of the viewport — the Eazo mobile app overlays a native toolbar there that your code cannot detect.
- No background music and no autoplay audio.
- Complete real states: loading, empty, success, error where relevant. Every control must actually work — no alerts, console-log placeholders or fake results.
- Visual bar: rich, generous visual feedback on every touch (motion, particles, deformation, color, light) while keeping exactly ONE core rule understood within 3 seconds. Canvas 2D preferred for effects; do not use the canvas roundRect API (older iOS Safari lacks it). Never hardcode light text colors onto possibly-light backgrounds — derive text color from the theme.