Doesn't handle CSS variables

[easrng]

Description

On any page that uses CSS variables CSS Used fails to copy the variable definitions.

Expected result.

CSS Used copies the CSS variables

:root{--color:#333;}div.somediv{color:var(--color);}

Actual result.

div.somediv{color:var(--color);}

[XARON]

Same.

[quackdor]

neeeeed!

[Ryan Linnane]

this would be very nice to have