dsadasdasdasasdasas/ObsidianCPP — reverse-engineered prompt

Build me a C++20 library that recreates the Obsidian Roblox Lua UI style as an immediate mode desktop UI. I want users to be able to create windows with tabs, group boxes, toggles, and other controls from simple C++ calls, then render it inside their own app.

Please make it work as a standalone window using GLFW and OpenGL, but also support Win32 input with OpenGL, Direct3D 11, and Direct3D 12 rendering so it can be drawn as an overlay inside an existing program. Include examples for a normal desktop window, a transparent Win11 overlay, and Direct3D hook style usage.

Use CMake with vcpkg, target C++20, and let it build either as a static lib or DLL. Bake the default font and icon assets into the library so people do not need to ship an assets folder. Add clear README instructions and minimal sample code. Look up current docs online if needed.