.tooltiptext {
  position: absolute;
  visibility: hidden;
  color: #fff;
  background-color: #333;
  transform: translateX(-50%);  /* Center by moving tooltip 50% of its width left */
  left: -8px;   /* Half of the width of the icon */
  top: -35px;
  font-size: 0.8em;
  text-align: center;
  border-radius: 6px;
  padding: 5px 8px;
  margin: 5px;
  z-index: 1000;
}
.tooltipped .tooltiptext {
  visibility: visible;
}