Actually, I should correct myself - yes, the breakdown in terms of technology is HTML, CSS, JS but the underlying abstraction is actually - structure, presentation and functionality.
This is where, imho, Svelte really shines. It helps you to map your mental model of structure, presentation and functionality to it's corresponding implementation of HTML, CSS, JS with a sprinkle of syntactic sugar. This goes way far in keeping the code easy to understand and maintainable in my opinion.