KSS is no longer in use anywhere. The only official style guide is
at https://design.wikimedia.org/style-guide.
Depends-On: I688a78e9a71a082c499af55bd01e8fd615130486
Change-Id: I21663c7b48465b0f23f1b40520e8cee9be71c4bc
minerva.variables.less: added gray color variable
MainMenu.less: added shadow to navigation
NotificationOverlay.less: changed alpha color of shadow
drawers.less: replaced rgba color with the same color variable
Bug: T231205
Change-Id: Ib1e16804b941a8f3b0cc639673baf73dc749a60a
* Remove ambiguity in imports - say the file extension
'less' for all instances of variables and mixins.
* Separate toast styles from drawer styles so they can be
imported separately
* associate header-action selector with its parent
(.overlay-header) not parent's parent (.overlay) so it can be imported
and rendered without the Overlay.
Change-Id: Ib7e19a440ba095d6424d35305fb41d643ca9764c
