Created attachment 158661 [details]
-webkit-calc is not evaluating vh/vw units
related: https://bugs.webkit.org/show_bug.cgi?id=91554. It looks like the original implementor of the vw/vh units in WebKit is not coming back to fix these issues.
*** Bug 103774 has been marked as a duplicate of this bug. ***
The Chrome team has reportedly fixed this in Blink:
Any chance for a backport in the near future as this is a major issue for layout design ?
This has been fixed with the patch for Bug 87846.