This makes the element symmetric and reduces the size of the hit target.
With the previous styling, the mid-circle glyph was sometimes offset from the center.
Furthermore, the large font size increased the hit box of the ::after element, eating into the scroll up arrow button's hit target.
It might be a good idea to give the ::after element pointer-events:none so that the scroll up button is clickable in its entirety.
Signed-off-by: Markus Stange <mstange@themasta.com>
Adds a `$res` SCSS variable set to the path from the root SCSS file to the `res`
directory.
This is a different base path than previously used in CSS URLs (it goes up 3
directories instead of 2), because Webpack will now be resolving images relative
to the root SCSS file, so the path corresponds to a source tree location,
instead of a path in the build output tree.
Defining this variable has two main goals:
* URLs are a bit easier to read
* The path can be overridden, which is needed for external (riot-web) themes
