Harness status: OK Found 16 tests 15 Pass 1 Fail Pass var() references work with registered properties Pass References to registered var()-properties work in registered lists Pass References to mixed registered and unregistered var()-properties work in registered lists Pass Registered lists may be concatenated Pass Font-relative units are absolutized when substituting Pass Calc expressions are resolved when substituting Pass Lists with relative units are absolutized when substituting Pass 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 [, 10px] Pass Valid fallback does not invalidate var()-reference [ | , red] Pass Valid fallback does not invalidate var()-reference [ | none, none] Pass Invalid fallback doesn't invalidate var()-reference [, red] Pass Invalid fallback doesn't invalidate var()-reference [ | none, nolength] Pass Invalid fallback doesn't invalidate var()-reference [, var(--novar)] Pass Empty universal custom property can be substituted with var()