Advanced AI Prompt for Text-Magnifier Cursor with Intersection Observer

Act as an Accessibility and Creative UI Developer. Build a highly functional custom cursor that physically acts as a real-time magnifying glass specifically for text-heavy editorial sections. The floating lens DOM element must enforce a [ZOOM_LEVEL] magnification (e.g., `2.5x`) and maintain a strict [LENS_SIZE] diameter framed by a [BORDER_STYLE]. Architect this effect utilizing either a secondary, hidden HTML5 Canvas that redraws the DOM, or a heavily optimized CSS `transform: scale()` paired with `overflow: hidden` on cloned content. Critically, integrate an `IntersectionObserver` to forcefully enable the heavy CPU magnifying calculations *only* when the cursor actually breaches the 'main' article container. Ensure the underlying text nodes remain fully selectable and highlightable, and that the screen reader DOM focus is absolutely uncorrupted by the lens element.