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 dependencies. Rendering: 2D Canvas API. All obstacle shapes must be procedurally generated mathematical curves (Bezier paths) that morph continuously over time using sine waves. Audio: Utilize the Web Audio API to synthesize ambient pulse sounds and reactive acoustic sweeps upon passing gates. Design style: Zen-like abstract art style. Uses a monochromatic pastel palette with deep soft shadows (shadowBlur on canvas) to emphasize spatial depth and fluid motion.