Server-side I use https://lib.rs/syntect https://lib.rs/syntect, which supports Sublime Text language definitions and themes. BTW: the markup grows substantial

Server-side I use https://lib.rs/syntect https://lib.rs/syntect, which supports Sublime Text language definitions and themes. BTW: the markup grows substantially. It's worth having a simplification step. Also the old-school <tt> element is shorter and cooler than <span>.