small {
  color: #999;
}

.highlight {
  color: #fff;
}

small {
  color: #999;
}

.highlight {
  color: #fff;
}

/**
 * Article info.
 */

.article-info__topics li:after {
  content: ', ';
}

.article-info__topics li:last-of-type:before {
  content: ' and ';
}

.article-info__topics li:last-of-type:after {
  content: '';
}

.article-info__topics li:first-of-type:before {
  content: '';
}

Add commas and "and" around topics.
Add commas and "and" around topics.
