.timeline {
  width: 100%;
  height: 480px;
  padding: 20px;
  position: relative;
  box-sizing: border-box;
  background: #fff;
  overflow: auto;
  display: flex;
}

.timieline-title {
  font-size: 1.5em;
  font-weight: bold;
}

.timeline-content {
  max-width: 300px;
  height: 201.6px;
  padding: 20px;
  flex-shrink: 0; 
  flex-grow: 0;
  align-self: flex-start;
  background: #f3f3f3;
  position: relative;
  border-radius: 10px;
  margin-right: 10px;
  box-shadow: 0px 0px 2px 2px rgba(0, 0, 0, 0.2);
}

.timeline-content:before {
  position: absolute;
  width: calc(100% + 14px);
  height: 4px;
  top: calc(100% + 10px);
  background: #919191;
  content: "";
  left: -7px;
  border-radius: 5px;
}

.timeline-content:after {
  position: absolute;
  width: 4px;
  height: 25px;
  top: 100%;
  left: calc(50% - 10px);
  background: #919191;
  content: "";
}

.timeline-period {
  position: absolute;
  top: calc(100% + 25px);
  background: #707070;
    color: #fff;
  padding: 10px;
  width: 100px;
  text-align: center;
  border-radius: 10px;
  left: calc(50% - 60px);
}

.timeline-period:before {
  width: 15px;
  height: 15px;
  background: #9b1a1e;
  border-radius: 50%;
  content: "";
  position: absolute;
  top: -20px;
  left: calc(50% - 6px);
  z-index: 2;
}

.timeline-content:nth-child(even) {
  align-self: flex-end;
}

.timeline-content:nth-child(even):before {
  top: -13px;
}

.timeline-content:nth-child(even):after {
  top: -25px;
}

.timeline-content:nth-child(even) .timeline-period {
  top: -60px;
}

.timeline-content:nth-child(even) .timeline-period:before {
  top: calc(100% + 2px);
}