_projects.scss

/**
 * Field styles
 */
.field-project-tags {
  > .field-items {
    // clearfix
    > .field-item {
      // Media Query mixin, go!
      @media (min-width: 600px) {
        // some sweet Susy code
        // we want 3 equal columns of tags
        @include gallery(4);
      }
    }
  }
}