.number-with-currency {
  &-symbol {
    min-width: 2.5em;
    text-align: center;
  }

  &-amount {
    text-align: right;
  }

  &-addon {
    width: 5.5rem;
    text-align: left;
  }

  & &-select {
    padding: 0;
    background: #fff;

    select {
      @extend .c-select;

      display: inline-block;
      width: 100%;
      height: 31px;
      border: 0;

      &::-ms-expand {
        // Required to see full text of selected value on IE11
        display: none;
      }
    }
  }
}

.number-with-currency {
  &-symbol {
    min-width: 2.5em;
  }

  &-amount {
    text-align: right;
  }

  &-addon {
    width: 5.5rem;
    text-align: left;
  }

  & &-select {
    padding: 0;
    background: $input-bg;

    select {
      @extend .c-select;

      width: 100%;
      height: $input-height;
      border: 0;

      &::-ms-expand {
        // Required to see full text of selected value on IE11
        display: none;
      }
    }
  }
}

Use bootstrap variables in number_with_currency
Use bootstrap variables in number_with_currency
