open-nomad/ui/app/styles/components/tooltip.scss

.tooltip {
  position: relative;
}

.tooltip::after {
  content: attr(aria-label);
  background: $black;
  border-radius: $radius;
  display: inline-block;
  opacity: 0;
  max-width: 250px;
  color: $white;
  font-size: $size-7;
  overflow: hidden;
  text-overflow: ellipsis;
  line-height: 1.25;
  white-space: nowrap;
  vertical-align: middle;
  padding: 5px 10px;
  margin: 0;
  position: absolute;
  z-index: $z-tooltip;
  bottom: 100%;
  left: 50%;
  transform: translateX(-50%);
  pointer-events: none;
  transition: bottom 0.1s ease-in-out;
}

.tooltip::before {
  pointer-events: none;
  display: block;
  opacity: 0;
  content: '';
  width: 0;
  height: 0;
  border-top: 6px solid $black;
  border-right: 6px solid transparent;
  border-left: 6px solid transparent;
  position: absolute;
  top: 0;
  left: 50%;
  margin-left: -6px;
  z-index: $z-tooltip;
  transition: top 0.1s ease-in-out;
}

.tooltip:hover::after {
  opacity: 1;
  bottom: 120%;
}

.tooltip:hover::before {
  opacity: 1;
  top: -20%;
}