Fixes: #4164

Please note that I used AI to create the solution. From what I can tell from my limited understanding of Go this solution makes sense. What I can not determine:

• Is the function I added the best way of achieving this result?
• Is this in line with your style of writing Go?
• Should the function be in that specific file?
• Did I miss any test cases for subtle interaction with other features?

This change fixes the following use case:

input

a {
  &::before {
    @media screen {
      ...
    }
  }
}

before

@media screen {
  {
    ...
  }
}

after

@media screen {
  &::before {
    ...
  }
}