Explain why two fingertips never really touch, as an interactive visualization in one HTML file. Start on two fingertips about to meet, then zoom in step by step: skin, cells, molecules, atoms, until the viewer sees the electron clouds pushing back before anything actually touches. Show the scale at each step and keep the explanation short and clear, like a great science video. It should play by itself in about 20 seconds when the page opens, then let me drag, scroll or replay to explore. Make it one HTML file that opens offline: no CDN links and no network requests. If you use a library like Three.js, put it inside the file. No image files, no image or video models.