connection .line .arrow {
  top: -5px;
  height: 0px;
  width: 0px;
  position: absolute;
  border-bottom: 6px solid transparent;
  border-top: 6px solid transparent;
  background-clip: border-box;
}
connection .line .arrow-fw {
  border-right: 12px solid black;
}

connection .line .arrow-bw {
  left: 100%;
  border-left: 12px solid black;
  transform: translateX(-12px);
}

connection .line .text {
  position: absolute;
  top: 100%;
  left: 50%;
  transform: translate(-50%, -100%);
}

connection .line {
  position:absolute;
  height:2px;

  background-color: black;
}