Mastodawn

If anyone is interested in some of the history and alternatives suggested:
https://github.com/w3c/csswg-drafts/issues/1771

(yes, that was me being annoying 9 years ago; but thank you to everyone for getting this tricky thing to work).

[css-sizing] Auto-resize iframes based on content · Issue #1771 · w3c/csswg-drafts

In https://lists.w3.org/Archives/Public/www-style/2017Aug/0045.html, Craig Francis said: Just re-raising the suggestion of allowing an iframe or textarea to increase its height based on its content...

GitHub

Intent to Ship: Responsively-sized <iframe>

[css-sizing] Auto-resize iframes based on content · Issue #1771 · w3c/csswg-drafts