.tooltipster-base {
  background: grey;
  border: 1px solid rgba(0,0,0,0);
  border-radius: 6px;
  box-shadow: 2px 2px 2px 0 rgba(0,0,0,0.4);
}

 .tooltipster-content {
  color: white;
  padding: 4px;
  line-height: 0.5em;
}