Frontend/static/styles/tooltipster/themes/tooltipster-noir.css

.tooltipster-noir {
  border-radius: 0px;
  border: 3px solid #2c2c2c;
  background: #fff;
  color: #2c2c2c;
}
.tooltipster-noir .tooltipster-content {
  font-family: 'Georgia', serif;
  font-size: 14px;
  line-height: 16px;
  padding: 8px 10px;
}