Use transparent black instead of mixing and shading colors
Currently the stylesheet has quite a lot of places like:
// special case hover colors inside a headerbar
headerbar windowcontrols button {
&:hover {
@include button(undecorated-hover,$c:darken($headerbar_bg_color,6%));
}
&:active,
&:checked { @include button(undecorated-active,$c:darken($headerbar_bg_color,10%)); }
}
This wouldn't be needed if it was transparentize(black, .1)
or a similar color.
This can also help with #53 as it's adaptive.