.timeline {
  overflow-y: auto;
  height: 100%;
  padding-right: 16px;
}
.timeline-item {
  padding-left: 30px;
  position: relative;
}
.timeline-item-head {
  width: 14px;
  height: 14px;
  border: 2px solid #D7D7D7;
  border-radius: 50%;
  position: absolute;
  top: 7px;
  left: 0;
  z-index: 1;
  background-color: #fff;
}
.timeline-item-head:before {
  content: '';
  display: block;
  width: 4px;
  height: 4px;
  border-radius: 50%;
  background-color: #D7D7D7;
  position: absolute;
  top: 3px;
  left: 3px;
}
.timeline-item-right {
  position: absolute;
  top: 13px;
  left: 12px;
  border-top: 2px solid #D7D7D7;
  width: 10px;
}
.timeline-item-tail {
  position: absolute;
  height: 100%;
  border-left: 2px solid #D7D7D7;
  top: 7px;
  left: 6px;
  z-index: 0;
}
.timeline-item:last-child-tail {
  top: -7px;
}