patternfly/dist/less/accordion.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.

.fixed-height-accordion-pf {
  display: flex;
  flex-direction: column;

  .panel {
    display: flex;
    flex-direction: column;

    &.panel-open {
      flex: 1;
    }

    .collapse.in {
      flex: 1;
      overflow-y: auto;
    }
  }
}