openecomp-ui/resources/scss/components/_sequenceDiagram.scss

.sequence-diagram {
  @extend .flex-column;
  .sequence-diagram-sequencer {
    flex: 0 1 auto;
    margin-bottom: 30px;
  }
  .sequence-diagram-action-buttons {
    flex: 0.1;
    text-align: center;
  }
}