microsoft/fluentui ? reverse-engineered prompt

Build me a Fluent UI component library and demo site for the web, with a clean Microsoft style look and a focus on reusable UI pieces for React apps.

I want a home page that shows the main components in a nice gallery, with buttons, inputs, menus, dialogs, cards, and form controls, plus examples of light and dark themes. It should feel polished and accessible by default, with keyboard friendly interactions and good spacing, typography, and colors.

Please also include a docs or storybook style experience so I can browse each component, see how to use it, and copy simple examples. If it makes sense, show both the newer React component approach and a path for using web components, so teams can adopt it gradually. Use current docs online if you need to, and make the code easy to extend with more components later.