hr {
  background: grey;
  border: 0;
  height: 1px;
  width: 20%;
  position: relative;
  margin: 30px auto;
  overflow: visible;
}
hr:before {
  content: "";
  width: 7px;
  height: 7px;
  background: grey;
  display: inline-block;
  border: 2px solid grey;
  transform: rotate(45deg);
  position: absolute;
  top: -5px;
  left: 50%;
  margin: 0 0 0 -4px;
  box-sizing: unset;
}