CSS code highlighting on some properties not working

[alexr00]

Prerequisites

• Put an X between the brackets on this line if you have done all of the following:
  • Reproduced the problem in Safe Mode: https://flight-manual.atom.io/hacking-atom/sections/debugging/#using-safe-mode
  • Followed all applicable steps in the debugging guide: https://flight-manual.atom.io/hacking-atom/sections/debugging/
  • Checked the FAQs on the message board for common solutions: https://discuss.atom.io/c/faq
  • Checked that your issue isn't already filed: https://github.com/issues?utf8=✓&q=is%3Aissue+user%3Aatom
  • Checked that there is not already an Atom package that provides the described functionality: https://atom.io/packages

Description

When using some of the newer properties, code highlighting does not work:

Strangely enough, other just-as-new props are being correctly highlighted.

Steps to Reproduce

Reproduces with this snippet:

.quotation {
	position: relative;
	padding-block: 1.rem;
}

Expected behavior:

position and padding-block have the same scopes.

Actual behavior:

position scopes:
support.type.property-name.css
meta.property-name.css
meta.property-list.css
source.css

padding-block scopes:
meta.property-name.css
meta.property-list.css
source.css

Reproduces how often:

100%

Versions

Additional Information

Originally from @hansgrimm in microsoft/vscode#142658

[eritbh]

My PR #193 might fix this?