jegeas/comparador_javier ? reverse-engineered prompt

Build me a simple web app that helps compare the water service regulations and show the differences in a clear way.

I want to be able to open the site, load or choose the included documents, and see a friendly comparison between the old regulation and the new one, with the important changes highlighted in plain language. It should feel easy to use, with a clean page, some basic navigation, and a results view that makes it obvious what changed.

If there are missing pieces or the PDFs need to be processed in a special way, figure that out and make it work end to end. Keep the interface simple and readable, and make sure it runs locally without much setup. If you need to look up current docs online for anything, go ahead.