span.TooltipTrigger {
  border-bottom: 3px solid #67C8EA;
  cursor: pointer;
  transition: all 0.3s ease;
}
span.TooltipTrigger:hover {
  background: #A4E1F6;
}

.TooltipTrigger {
  border-bottom: 3px solid #67C8EA;
  cursor: pointer;
  transition: all 0.3s ease;
  position: relative;
  background-color: yellow; /* Highlight */
  padding: 2px 4px;
}

.TooltipTrigger:hover {
  background: #A4E1F6;
}