Advanced AI Prompt for Infinite Grid Tunnel Shaders

Act as a Retro-Futuristic Technical Artist. Write a pure GLSL fragment shader that mathematically renders an infinite, hypnotic 'Synthwave' or 'Tron' style grid tunnel navigating through 3D space, mapped entirely onto a flat 2D plane. You must utilize advanced Cartesian-to-Polar coordinate transformations to forcefully warp a standard 2D grid into an aggressive 3D vanishing-point perspective. Expose the [GRID_SPACING] as a dynamic uniform. Implement a non-linear [TUNNEL_CURVATURE] function that instantly reacts and bends based on the user's normalized mouse X/Y coordinates. The visual progression through the tunnel must travel at a constant [SPEED] linked to `uTime`. Apply a high-contrast, emissive [GLOW_STRENGTH] to the grid lines, strictly enforcing an exponential alpha falloff (`exp()`) based on the fragment's distance from the absolute center focal point to simulate deep darkness at the end of the tunnel.