@container support needs to be added

[jogibear9988]

Expected Behaviour

@container rules should be parsed

Actual Behaviour

they are not parsed

Reproduce Scenario (including but not limited to)

@container (min-width: 700px) {
  .card h2 {
    font-size: 2em;
  }
}

[holblin]

Thanks a lot for your contribution! Sorry I wasn't able to review and merge earlier. A new version should be available soon on npmjs 👍