adamgiebl/neumorphism ? reverse-engineered prompt

Build me a simple React web app for experimenting with Neumorphism, also called Soft UI. I want a clean page where I can tweak the look of a soft raised or pressed surface, see the result update right away, and get the CSS code generated for me so I can copy it into my own project.

Make it feel polished and easy for a designer or beginner to use. There should be a live preview of the shape, controls for the main visual settings like background color and shadow style, and a clear copy to clipboard action for the CSS. If it makes sense, let people switch between raised and inset effects and adjust things like corner roundness and shadow intensity.

Keep the interface modern and minimal, with the preview as the main focus. Please wire it up so it runs locally with the usual start command, and look up current docs online if you need to fill in any React details.