Ravikumarmalhotra/KKSO-KBGA-APP ? reverse-engineered prompt

Build me a simple web app for the K K S O K B G A orange line that works well on desktop and mobile.

It should feel like a small internal tool, with a clean home screen that lets users open pages for battery checking, failure entry, failure testing, maintenance entry, maintenance testing, fire pump running analysis, and a couple of simulation pages. Make it easy to move between these screens and keep the look consistent across the whole app.

I also want it to behave like a proper installable app, so include the app icon support and offline friendly behavior if that makes sense. Use the existing JavaScript and CSS files to keep everything organized, and make sure the forms and pages actually work together smoothly. If you need to, look up current browser friendly practices online.