bikashdev01/sidebar — reverse-engineered prompt

Build me a simple, polished sidebar menu project that feels ready to drop into a website or dashboard. I want a left side navigation that can collapse and expand, highlight the active section, and feel smooth when you open or close it. It should look clean and modern, with a few sample menu items, icons if they make sense, and a main content area so I can see how the sidebar works in a real layout.

Please make it responsive so it works nicely on desktop and mobile, with a menu button on smaller screens. Add basic hover states, smooth transitions, and sensible spacing and colors. Keep the code easy to understand and easy to tweak later, since I may want to reuse it for other projects.

If the repo is basically empty, just create the whole thing from scratch in the simplest way that makes sense. Include whatever small demo content is needed so I can open it and immediately see the sidebar working. Look up current docs online if you need to.