leptos-rs/leptos ? reverse-engineered prompt

Build me a small Rust web app with Leptos that feels modern and fast in the browser.

I want a simple site with a homepage, an about page, and a few interactive parts like a counter, a form, and a list that updates without full page reloads. Please make it work with server side rendering and hydration so it loads quickly, then becomes interactive on the client. Use Leptos patterns for components, signals, routing, and server functions, and keep the code clean enough that I can extend it later.

If it helps, look up the current Leptos docs online for the best way to wire things up. I’d also like the app to have a nice basic layout, sensible error handling, and a small example of data fetching from the server so I can see how the full stack flow works end to end.