wpgraft reads the page as your browser rendered it, the real elements and the real computed styles, at every breakpoint you ask for, and rebuilds it as Elementor’s own native elements with the styles in Elementor’s own fields. It does not care that a language model wrote the HTML, and it does not care what framework the page was built with: by the time wpgraft looks, all of that has already become computed styles.
Claude will write you a whole landing page in one go, and then you own an HTML file, which is fine until the client asks for a different headline. This is the step that turns it into something a client can edit: the generated page is rebuilt as Elementor’s own elements, so the next change is a click in the panel rather than another prompt.