<style> blocks respectively. You can even find some inline CSS in the
onclick (and other events) attribute of HTML elements.
There is actually a remarkable number of examples of this behaviour: The different blocks in Vue’s Single-File Components, the sections in Svelte’s components or the frontmatter syntax and JSX-based component template of Astro’s components.
As such, Volar was built on the principle that it is highly likely that your language will have such embedded languages and has top-notch support for them. Notably, Volar can drastically simplify the mappings needed to get editing features working across the different parts of your files.
If your language does not have embedded languages: That’s completely okay! Volar will still work for you just as well, and it will be ready if one day you do decide to add embedded languages to your language.