A little #MathML question: is there a way of putting stretchy braces around arbitrary HTML without using JavaScript to resize them?
I've made a thing using ResizeObserver to set the size of stretchy braces to (roughly) the size of the contents: https://resize-brace-wrapper.think.somethingorotherwhatever.com/
Before and after the contents, I have a <math> element containing a stretchy <mo> and an <mspace> whose height is set to the heights of the contents. I couldn't find a foreign element tag in MathML Core, which would let me do it with a single <math> tag.