.number {
  width: 50px;
  height: 50px;
  position: relative;
  text-align: center;
  display: inline-block;
  font-size: 36px;
  background-color: #9aacb7;
  color: #fff;
  line-height: 50px;
}

.timeline .row {
  position: relative;
  z-index: 5;
}

/* Para filas impares (1, 3, 5...) */

.timeline .col-6.col-md-4.text-md-start.text-center {
  margin-top: 1em;
}

/* Para filas pares (2, 4, 6...) */
.timeline .row:nth-child(even) .col-lg-1 {
  order: 0;
}

.timeline .row:nth-child(even) .col-6.col-md-4.text-md-end.text-center {
  order: 1;
  margin-top: 1em;
}

.timeline .row .col-12.col-md-4.mt-4.mt-md-0 {
  order: 3;
}

@media (min-width: 768px) {
  .timeline::before {
    content: "";
    position: absolute;
    width: 1px;
    background-color: #9aacb7;
    top: 5%;
    bottom: 0;
    left: 50%;
    margin-left: -2px;
    height: 91%;
    z-index: 1;
  }

  .number::before {
    content: "";
    position: absolute;
    height: 1px;
    background-color: #9aacb7;
    width: 400%;
    top: 50%;
    left: -150%;
    z-index: -1;
    display: inline-block;
  }

  .timeline .row:nth-child(even) .col-lg-1,
  .timeline .row .col-12.col-md-4.mt-4.mt-md-0,
  .timeline .row:nth-child(even) .col-6.col-md-4.text-md-end.text-center {
    order: inherit;
  }
}