rlh unitThe rlh CSS length unit is a font-relative length relative to the line height of root element.unitsUnitswidely2023-11-212026-05-21https://drafts.csswg.org/css-values-4/#font-relative-lengthshttps://developer.mozilla.org/docs/Web/CSS/Reference/Values/lengthcss.types.length.rlhhttps://nowyoucanuse.com/features--rlh.html