Gravity Flux Flappy Engine

I want you to act as a top-tier physics-based gameplay programmer. Produce a SINGLE FILE (index.html) build of an architectural flight evasion game. GAME SPEC: Title: Gravity Flux Core mechanic: Navigate a self-inflating soft-body sphere through an environment of closing and expanding organic geometric gaps. Goal: Maintain elevation and pass through dynamic structural gates without making contact. TECH REQUIREMENTS: Single file: Combined HTML, CSS, and vanilla JavaScript with no dependenci...