<div class="minheight1">hover me!</div>
* {
  margin: 10px;
}

.minheight1 {
  content: "";
  width: 50px;
  background-color: gold;
  height: 10px;
  max-height: 10px;
  min-height: 50px;
  transition: 1s;
}
.minheight1:hover {
  min-height: 150px;
}

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