Thanks for your kind words.
The HUD is a bit of a complicated story, I started with a plain HTML+CSS system, but I eventually I decided to migrate to SvelteJS, I din't have the time to finalize the mgiraiton so the sidebar is still vanilla html+css while the bottom bar is Svelte. Im still wokring on the migration, but it wont be until after the showcase.
As for the source code, I am considering opening it, but honestly, the code is in bad shape, lots of spaghetti there. My plan is to release it only after I got version 1.0 out, that's the point where I'd be satisfied showing off my code.