For information: the limit is above ten million pixels in all browsers, and containers that large are occasionally genuinely useful.
(See https://news.ycombinator.com/item?id=34299569, among other places I’ve remarked on it. Note that that’s just testing the limits of declared CSS values; I haven’t tested whether you can obtain larger values by containing multiple large children rather than specifying an absolute height. Can’t find any place where I documented Chromium’s value for some reason, but it seems to be 11,184,809 pixels, five less than a third of WebKit’s value, with the same clamping behaviour.)
