Do you want to know how the CSS WG works? Fantasai has written about:csswg, An Inside View of the CSS Working Group at W3C.
parent-var()to Level 2.
parent-var()as work item.
The CSS Working Group chose not to adopt a
$foo syntax and to continue using a functional notation for this feature for several reasons:
$fooand cannot be duplicated on the server side.
$foousually treat them as macro expansions that can be used anywhere, for example to shorten selectors or to represent multiple declarations in a declaration block.
$fooleaves this syntax open to future extensions of CSS and allows either server-side macros or a future CSS macro expansion feature to co-exist with cascading variables.
var(foo, fallback-value)) or using the parent’s scope (
parent-var(foo)) to be simple extensions consistent with the basic syntax.
For further reading on this topic, see “Let’s Talk about CSS Variables” by Tab Atkins (CSSWG spec editor) and “CSS Variables, why we drop the $foo notation” by Daniel Glazman (CSSWG co-chair).