patternfly/dist/less/dependencies/bootstrap/mixins/center-block.less

This reference implementation of PatternFly is based on [Bootstrap v3](http://getbootstrap.com/). Think of PatternFly as a "skinned" version of Bootstrap with additional components and customizations.

// Center-align a block level element

.center-block() {
  display: block;
  margin-left: auto;
  margin-right: auto;
}