metamask-extension/ui/components/app/network-account-balance-header/index.scss

.network-account-balance-header {
  border-top: 1px solid var(--color-border-muted);
  border-bottom: 1px solid var(--color-border-muted);

  &__network-account {
    &__ident-icon-ethereum,
    &__ident-icon-ethereum--gray {
      height: 18px;
      width: 18px;
      border-radius: 50%;
      border: 1px solid var(--color-background-default);
      background: var(--color-background-default);
      margin-inline-start: -10px;
      margin-top: -20px;

      > span {
        display: flex;
        justify-content: center;
        line-height: 18px;
      }
    }

    &__ident-icon-ethereum--gray {
      border: 1px solid var(--color-border-default);
    }
  }
}