Harness status: OK

Found 16 tests

7 Pass
9 Fail
Fail	var() references work with registered properties
Fail	References to registered var()-properties work in registered lists
Fail	References to mixed registered and unregistered var()-properties work in registered lists
Fail	Registered lists may be concatenated
Fail	Font-relative units are absolutized when substituting
Fail	Calc expressions are resolved when substituting
Fail	Lists with relative units are absolutized when substituting
Fail	Values are absolutized when substituting into properties with universal syntax
Fail	Invalid values for registered properties are serialized as the empty string
Pass	Valid fallback does not invalidate var()-reference [<length>, 10px]
Pass	Valid fallback does not invalidate var()-reference [<length> | <color>, red]
Pass	Valid fallback does not invalidate var()-reference [<length> | none, none]
Pass	Invalid fallback doesn't invalidate var()-reference [<length>, red]
Pass	Invalid fallback doesn't invalidate var()-reference [<length> | none, nolength]
Pass	Invalid fallback doesn't invalidate var()-reference [<length>, var(--novar)]
Pass	Empty universal custom property can be substituted with var()