I know, it's just that this place as far as I used to know, similarly to tumblr, wasn't standard HTML but rather a more limited form of it. Tbh I expected the embed to fail and thought it'd work like Twitter trying to use a link to add a video/image.
I guess it updated, the HTML is fully featured apparently, just no position: absolute and some z-index shit. (Plus CSS vars forms and Js is not available.)