resize iframe automatically

 javascript - Make iframe automatically adjust height according to the contents without using scrollbar? - Stack Overflow

That did not work, so tried going with width=100% height=25%

html - How do you give iframe 100% height - Stack Overflow 

Current code has something like

<iframe width="100%" style="height: 75vh;" 

etc. A bit ugly, and crops content which resizes automatically on mobile, but that will do for now.