Lately I have been pondering: why do all modern editors/IDEs use mono fonts? Used to be important for term based apps as it uses chars to draw the UI, but non term apps? "The indentation" - yeah, but space is equally wide in variable-width fonts... So I switched to Go for VSCode 🤷🏻and it's great!

Retested by copying the example (final) code to empty html and tested on MacOS latest (Safari, Firefox, Chrome), confirming, I cannot double click on the text covered by the extended header. Maybe I am not using the correct example (using "the final code")