metamask-extension/ui/components/app/edit-gas-fee-popover/index.scss

.edit-gas-fee-popover {
  @media screen and (min-width: $break-large) {
    max-height: 84vh;
  }

  &__wrapper {
    border-top: 1px solid $ui-grey;
  }

  &__content {
    padding: 16px 12px;

    &__header {
      color: $ui-4;
      font-size: 10px;
      font-weight: 700;
      margin: 0 12px;

      &-option {
        display: inline-block;
        width: 40%;
      }

      &-time {
        display: inline-block;
        width: 20%;
      }

      &-max-fee {
        display: inline-block;
        width: 30%;
      }
    }

    &__separator {
      border-top: 1px solid $ui-grey;
      margin: 8px 12px;
    }
  }
}