I'm making Causal Loop Diagrams. There are basically 2 kind of edges: positive edge (increase of input gives increase of output) and negative edges (increase of output gives decrease of output).

I would like to be able to define a class for green edges (the positive edges) and red edges (the negatives edges), and uses these classes throughout my diagram, e.g.:

A -->::g B
B -->::r C
C -->::g A

class g stroke:green
class r stroke:red

Something along those files (I know it is not correct Mermaid but it's just to give the idea).