metamask-extension/ui/app/components/transaction-view/index.scss

.transaction-view {
  flex: 1 1 66.5%;
  background: $white;
  min-width: 0;
  display: flex;
  flex-direction: column;
  overflow-y: auto;

  &__balance-wrapper {
    @media screen and (max-width: $break-small) {
      display: flex;
      flex-direction: column;
      justify-content: flex-start;
      align-items: center;
      flex: 0 0 auto;
      padding-top: 16px;
    }

    @media screen and (min-width: $break-large) {
      display: flex;
      flex-direction: row;
      justify-content: flex-start;
      align-items: center;
      margin: 2.3em 2.37em .8em;
      flex: 0 0 auto;
    }
  }
}