.track-start-marker {
  background-color: #007bff;
  color: #fff;
  width: 200px;
  height: 200px;
  border-radius: 100px;
  font-size: 0.6em;
  text-align: center;
  line-height: 200px;
  display: flex;
  align-items: center;
  justify-content: center;
}
.track-end-marker {
  background-color: #f00;
  color: #fff;
  width: 200px;
  height: 200px;
  border-radius: 100px;
  font-size: 0.6em;
  text-align: center;
  line-height: 200px;
  display: flex;
  align-items: center;
  justify-content: center;
}