Susheel929/saas-analytics-dashboard-production ? reverse-engineered prompt

Build me a clean single page SaaS analytics dashboard called PulseBoard.

It should let me switch between Dashboard, Analytics, Customers, and Settings using normal page style URLs, and the page should still work if I refresh on any of those sections. I want a dark, light, and system theme option that remembers my choice. Store the customer data in the browser so it stays after refresh, and make it easy to add, edit, delete, search, and filter customers by status.

The dashboard should show simple KPI cards based on the current customer records, and the analytics view should use the same data to show useful summary metrics. I also need CSV import and export for backups, with basic validation so bad files do not break things.

Make it responsive, fast, and polished, with safe rendering that does not rely on unsafe HTML injection. If you need to check the best current way to handle the routing or deploy fallback, look up the current docs online.