The problem
If you use hypens in your CSS selectors, it will generate a *.d.ts file that has compilation errors.
For example, the following SCSS file:

.main {
  border: 1px solid black;

  &--red {
    border-color: red;
  }
}

becomes:

// This file is automatically generated.
// Please do not change this file!
export const main: string;
export const main--red: string; // ERROR ON THIS LINE

The solution
At the very least, I think this tool should probably throw some kind of error. I'm not keen on the idea of making it transform into an identifier that doesn't map 1-1 with the original CSS selector name.

EDIT: I'd be interested to know what conventions you guys follow if it isn't BEM, ie. slight permutations on an element, such as it having an alternate color or skin.