Element Percentage Units - tomhodgins/process-css-demo GitHub Wiki
These units are similar to CSS's Viewport-Percentage units (e.g. vw or vmax) except instead of representing 1% of the browser viewport's height or width, these units refer to 1% of the rendered height or width of the element matching the rule.
<number><unit>
-
<number>is any number CSS understands -
<unit>is one of--ew,--eh,--emin,--emax
The --ew unit represents 1% of the element's rendered width, so a dimension like 10--ew would represent 10% of the element's rendered width:
font-size: 10--ew;The --eh unit represents 1% of the element's rendered height, so a dimension like 10--eh would represent 10% of the element's rendered height:
font-size: 10--eh;The --emin unit represents 1% of the element's rendered size, whichever is shorter between width or height, so a dimension like 10--emin would represent 10% of the element's shortest edge:
font-size: 10--emin;The --emax unit represents 1% of the element's rendered size, whichever is longer between width or height, so a dimension like 10--emax would represent 10% of the element's longest edge:
font-size: 10--emax;