Why does an iframe interfere with page scrolling in Firefox?

Question

HTML

When I insert, say, a slideshow through an iframe into a page, when I access the site through Firefox and hover the mouse over the slideshow (the cursor is within the iframe), the page will not scroll with the mouse wheel. This "feature" causes great inconvenience. How to solve the problem?

Answer 1

Obviously, either make the content of the document loaded in the iframe smaller than the viewport of its root element, or disable scrolling in it:
CSS (in the loaded document)

html {
  overflow:hidden
}