No, unfortunately. The issues is that mixins applied via a pre-processor don't need to take into account the complexities of the cascade. Designing a mixin sys

No, unfortunately. The issues is that mixins applied via a pre-processor don't need to take into account the complexities of the cascade. Designing a mixin system that works as part of the cascade is hard, and so no one has yet proposed a system that everyone is happy with. This is the same reason we can't use var() within media queries to define breakpoints. Custom properties are part of the cascade and so are attached to a dom element, media queries have no dom element attached to them. (The proposed custom environment variables with env() will solve this one)