custom classes for typespec keywords

Currently using "monokai-shade" theme and the styles on typespec keywords are nearly white which is quite "loud", visually distracts from the function definition itself, and unfortunately discourages me from writing typespecs. 😞

I'd love to be able to target and adjust the styles on typespec keywords, e.g.:
- `@type type_name :: type`
- `@typep type_name :: type`
- `@opaque type_name :: type`
- `@spec function_name(type1, type2) :: return_type`
- `@callback function_name(type1, type2) :: return_type`
- `@macrocallback macro_name(type1, type2) :: Macro.t`

I'm thinking similarly to the `syntax--documentation` class added to `@doc` moduledocs, tacking on an extra class like `syntax--typespec` or something.

Any thoughts?