metamask-extension/ui/components/app/step-progress-bar/index.scss

.progressbar {
  counter-reset: step;
  display: flex;
  justify-content: space-evenly;
}

.progressbar li {
  list-style-type: none;
  width: 25%;
  float: left;
  font-size: 12px;
  position: relative;
  text-align: center;
  text-transform: uppercase;
  color: #7d7d7d;
  z-index: 2;
}

.progressbar li::before {
  width: 30px;
  height: 30px;
  content: counter(step);
  counter-increment: step;
  line-height: 30px;
  border: 2px solid #d6d9dc;
  display: block;
  text-align: center;
  margin: 0 auto 10px auto;
  border-radius: 50%;
  background-color: white;
  z-index: -1;
}

.progressbar li::after {
  width: 100%;
  height: 2px;
  content: '';
  position: absolute;
  background-color: #d6d9dc;
  top: 15px;
  right: 62%;
  z-index: -1;
}

.progressbar li:first-child::after {
  content: none;
}

.progressbar li.active {
  color: $primary-blue;
}

.progressbar li.active::before {
  border-color: $primary-blue;
  z-index: 1;
}

.progressbar li.active + li::after {
  background-color: $primary-blue;
  z-index: -1;
}

.progressbar li.complete::before {
  background-color: $primary-blue;
  color: $ui-white;
}