#container {
  width: 100%;
  height: 300px;
}
.block {
  display: inline-block;
  width: 3%;
  height: 300px;
  background-color: black;
  position: relative;
}
.effect {
  position: absolute;
  bottom: 0;
  width: 100%;
  height: 50%;
  transition: height .1s;
  background-color: #00D700;
  box-sizing: border-box;
  border: 1px solid white;
}