discourse/app/assets/stylesheets/common/components/signup-progress-bar.scss

:root {
  --progress-bar-line-width: 1px;
  --progress-bar-circle-size: 0.5rem;
  --progress-bar-icon-size: 0.25rem;
}

.signup-progress-bar {
  width: auto;
  display: flex;
  box-sizing: border-box;
  margin-bottom: 1.2em;
  gap: 1rem;
  .account-created &,
  .activate-account & {
    margin-inline: 0;
  }

  &__segment {
    width: auto;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    color: var(--primary-low-mid);

    &:first-child .signup-progress-bar__circle {
      transform: translateX(50%);
      z-index: 1;
    }

    &:last-child {
      width: var(--progress-bar-circle-size);
      .signup-progress-bar__circle {
        transform: translateX(-50%);
        z-index: 1;
      }
    }
  }

  &__step {
    display: flex;
  }

  &__circle {
    flex-shrink: 0;
    font-size: var(--progress-bar-icon-size);
    color: var(--secondary);
    display: flex;
    justify-content: center;
    align-items: center;
    height: var(--progress-bar-circle-size);
    width: var(--progress-bar-circle-size);
    transform: none;
    border-radius: 50%;
    border: var(--progress-bar-line-width) solid var(--primary-low-mid);
    background-color: var(--secondary);

    .--active & {
      background-color: var(--success);
      border-color: var(--success);
      box-shadow: 0 0 1px calc(var(--progress-bar-circle-size) / 2)
        var(--success-low);
    }
    .--completed & {
      background-color: var(--success);
      border-color: var(--success);
    }
  }
}