Creating new format or style

I would like to easily add some styling to my notes (very little styling just to help me prioritize).
For that, I am using for example `` or == and that helps me greatly, but I would like to know how to be able to add a certain style for when I use ^^ or @@ (for example).

I was thinking about using css snippet but I have no idea about how would the css look like to have a certain format if the line starts with @@ or with ^^ (just like when it starts with `` or with == it has a style, see below)

The idea is to avoid using “long” html style such as <font style="color:green">Text Color</font>


thanks for any help !