The forms of a page as the form page type (/path/form) returns them: htmx swaps this element as a whole (see Form.html). While a request runs, htmx sets htmx-request on it and the overlay covers the form. Styled here and not in the theme build: the static pages around the island load the CSS of the TYPO3 10 export. The spinner takes the button colour of each theme.

{forms -> f:format.raw()}