Advanced AI Prompt for Image Masking Reveal Cursor

Act as a Creative Frontend Illusionist. Design an interactive 'flashlight' or 'x-ray' cursor effect that physically acts as a geometric window, revealing a completely hidden [REVEAL_IMAGE_URL] resting underneath a solid, dark top-layer overlay. The 'hole' in the overlay must be mathematically carved out using the exact [MASK_SHAPE] constrained to a [MASK_SIZE] diameter (e.g., 150px circle). Dictate the implementation using the highly performant CSS `clip-path: circle(size at X Y)` updated via JS custom properties, or alternatively, a Canvas `globalCompositeOperation = 'destination-out'` approach. You must provide a rigorous, graceful degradation fallback utilizing a standard semi-transparent radial gradient for legacy browsers that outright fail to render CSS masking paths. Crucially, the overlay and mask must possess `pointer-events: none` to guarantee the hidden text content underneath remains perfectly highlightable, selectable, and clickable.