Soften the popup border to the translucent sand-a2 token and inset the
separator (mx-3) so it lines up with item text instead of bleeding to
the panel edges, lightening it to sand-a3. Both now track the Figma
alpha hairlines and keep their dark-mode values via the Radix alpha
scale.
Also modernize the existing arbitrary-variant classes in this file to
Tailwind's shorthand syntax (data-[x]: -> data-x:, origin-[var(...)] ->
origin-(...)).
Signed-off-by: Émile Ré <emile@probo.com>
72f52c1ad7