R Shiny link to FluidPage, similar to Modal window

Question

I currently have an app in R shiny using fluidPage. Within this app i have an interactive data table from which I select rows which brings up a modal window. See sample code below.

    # Load packages
    library(tidyverse)
    library(readxl)
    library("openxlsx")
    library(segmented)
    library(grid)
    library(gridExtra)
    library(shiny)
    library(shinyWidgets)
    library(shinydashboard)
    library(DT)
    library(dplyr)
    library(shinyBS)
    library(shinythemes)

    data_table <- data.frame(c(1))
    names(data_table)[1] <- "a"
    data_table$b <- 2
    data_table$c <- 3

    ui <- fluidPage(theme = shinytheme("lumen"),

                    mainPanel(
                      tabsetPanel(
                        tabPanel("Dashboard",
                                 fluidRow(
                                   box(DTOutput("data_table"), title = "Selectable Data Table", width = 12)
                                 ),
                                 tags$head(tags$style(HTML('
                            .modal-lg {
                            width: 99%;
                            }
                          ')))
                    )
    )
    )
    )
    server <- function(input, output, session) {
        #DASHBOARD
      output$data_table <- DT::renderDataTable({
        DT::datatable(data_table, selection = 'single', escape = FALSE)
      })
      table_select <- reactive({
        input$data_table_rows_selected
      })
          observeEvent(table_select(),{
            showModal(modalDialog(
              title = "I wish this window had a layout similar to fliudPage",
              size = "l",
              easyClose = TRUE,

            )
            )
          })
    }

    shinyApp(ui = ui, server = server)

However, in this modal window, I am not able to have the fluidPage layout i.e. row width of 12, setting fluidRows etc. I would like to have greater control of the layout of this modal window - preferably the same layout controls as a fluidPage.

the only thing I have been able to do is to create a larger modal window than what is normally presented using the following code:

                                 tags$head(tags$style(HTML('
                            .modal-lg {
                            width: 99%;
                            }
                          ')))

The way I see it I have two options:

Option 1 - Find a way to have the observeEvent open a new fluidPage instead of a modal window? or

Option 2 - change the modal window layout somehow...

any help would be greatly appreciated!

Cheers,

-Alex