.legend {
  clear: both;
  margin: 20px;
  width: 35%;
  padding-left: 60%;
}

.tooltip {
  position: relative;
  display: inline-block;
}

.tooltip .tooltiptext {
  visibility: hidden;
  width: 120px;
  background-color: #666;
  color: #fff;
  text-align: center;
  padding: 5px 0;
  border-radius: 6px;
  line-height: 1.5;

  position: absolute;
  z-index: 1;
  bottom: 125%;
  left: 50%;
  margin-left: -60px;

  opacity: 0;
  transition: opacity 0.3s;
}

.tooltip .tooltiptext::after {
  content: "";
  position: absolute;
  top: 100%;
  left: 50%;
  margin-left: -5px;
  border-width: 5px;
  border-style: solid;
  border-color: #666 transparent transparent transparent;
}

.tooltip:hover .tooltiptext {
  visibility: visible;
  opacity: 1;
}