Tests ----- calc() and 5 divisions involving integers http://w3c-test.org/css/css-values/calc-integer.html testing z-index: calc(3 / 2) and testing z-index: calc(-3 / 2) http://w3c-test.org/css/css-values/calc-z-index-fractions-001.html Test results - - - - - - https://wpt.fyi/results/css/css-values/calc-integer.html?label=stable https://wpt.fyi/results/css/css-values/calc-integer.html?label=master https://wpt.fyi/results/css/css-values/calc-z-index-fractions-001.html?label=stable https://wpt.fyi/results/css/css-values/calc-z-index-fractions-001.html?label=master Safari 12, Safari Technological Preview and Epiphany Technological Preview (Epiphany Technological Preview 3.31.90-45-ga15d70306 with WebKitGTK 2.23.3) fail all the tests.
<rdar://problem/48405779>
This will be a very important feature for using custom properties with grids. It has been fixed in Firefox already. Here is a est-case with calc() in the grid-column-end property: https://codepen.io/mirisuzanne/pen/rgYKrd?editors=1100
Safari Technology Preview 154 is still failing this test: http://w3c-test.org/css/css-values/calc-z-index-fractions-001.html and so do Firefox Nightly 107.
*** This bug has been marked as a duplicate of bug 260777 ***