This is a bug to implement the calc-size() function. (This is partly CSS and partly layout.) See: * Specification: https://drafts.csswg.org/css-values-5/#calc-size * Explainer: https://github.com/w3c/csswg-drafts/blob/main/css-values-5/calc-size-explainer.md * Chromestatus: https://chromestatus.com/feature/5196713071738880 * WPT: https://wpt.fyi/results/css/css-values/calc-size
* WebKit standards position request: https://github.com/WebKit/standards-positions/issues/348
<rdar://problem/128487377>