I am having a usecase where the <footer> inside the <iframe> should be sticky at bottom (<iframe> doesn't have a scrollbar) based on the parent document scroll.
Note:
position: sticky works as expected inside <iframe> only when it has a scroll.
Please share your thoughts.
Their is not a way to do this with css of standard browser APIs. You might however find it useful to look at a library called iframe-resizer which provides an API to tell the iframe the scroll position of the parent page.
You would then need to write a little bit of JS to take this stream of position data and use it to position your div.