:root {
  --csv-list-separator: ',';
}
%csv-list {
  // mainly used for block elements, you may need to overwrite this with an
  // inline-flex to keep any inline-ness
  display: flex;
}
%csv-list > * {
  @extend %csv;
}
%csv:not(:last-child)::after {
  display: inline;
  content: var(--csv-list-separator);
  margin-right: 0.3em;
}