/* append a coma after each child */
span.tags {
  display: inline;
  margin: 0;
  padding: 0; }

span.tags span {
  display: inline;
  margin: 0;
  padding: 0; }

span.tags span:after {
  content: ", ";
  color: #aaa; }

span.tags span:last-child:after {
  content: ""; }