Shiny Dashboard: DataTable in Skin "midnight" + sizing of the table

Question

I am currently building a shiny dashboard with the skin "midnight" from shinydashboardPlus. In this app, I would like to show the data table. However, the default settings of the datatable do not seem to work with a dark background.

library(shiny)
library(shinydashboard)
library(shinydashboardPlus)
library(DT)

data('mtcars')

# User Interface
ui <- dashboardPage(skin =  "midnight",
                    dashboardHeader(),
                    dashboardSidebar(),
                    dashboardBody(
                                fluidRow(background = 'gray', DT::dataTableOutput('items_dt'))
                                )
                    )


server <- function(input, output, session) {  
  
  
  output$items_dt = DT::renderDataTable(
    mtcars,
    filter = 'bottom',
    options = list(scrollX = TRUE)
  )
  
}

shinyApp(ui, server)

Furthermore, I have the issue that the original data has rather long entries for some string variables. Is there a way to scale down the size of the table?

I tried to fix both issues with formatStyle. Unfortunately, I could not resolve the issues. Below is an example for trying to set the background color to white.

  output$items_dt = DT::renderDataTable({
    DT::datatable(
    mtcars,
    filter = 'bottom',
    options = list(scrollX = TRUE)
    ) %>% formatStyle(items_dt, target = 'row', backgroundColor = 'white')  
    }, server = FALSE)

Does anyone have experiences with including datatables in an shiny app using the "midnight" skin?

Thank you very much in advance!