Fixing top section in shiny

Hi all,

Is there a way to fix the top section of the dashboard here. Right now, the widgets (selectinput) are fixed, but when the user scroll down, it gets covered by the datatable. Can we not make sure this does not get covered and only datatable moves down?

library(shiny)
library(DT)
ui <- shinyUI(fluidPage(
  titlePanel(fluidRow(
    div(column(12, align="center",
           selectInput("rmd1", "RMDw", choices = c(1,2)),
           selectInput("rmd2", "RMD2", choices = c(1,2))
    ), style = "position:fixed; width:inherit;")
  )),
  br(),br(),br(),br(),br(),br(),br(),br(),br(),br(),br(),br(),br(),br(),br(),
  dataTableOutput("uioutput", height = "2000px")
  
))

server <- function(input, output, session) {
  output$uioutput <- renderDataTable({
    datatable(iris)
  })
}

shinyApp(ui, server)