My first attempt at putting all the pieces together to create a self-editable, zero toolchain, offline-first webpage with good debugger support. My CSS is quite weak so I need some more time to make it responsive and look cool, but the general idea is visible.

Interesting! What does “good debugger support” mean?

it means the idiomatic language debugger works (i.e. devtools), in contrast to shipping a facsimile which often happens with new coding environment. I would go slightly further and say the debugging experience is better than in normal Javascript because when code is updated to place a "debugger expression" it hot-reloads so then it immediately has the opportunity to catch an execution. debuggers + live coding have excellent synergy