title: How to extend the background in a shiny dashboard
body: <p>Here is a small (silly) code of a shiny dashboard application:</p>
  
  <pre><code>    library(shiny)
  library(shinydashboard)
  
  ui &lt;- dashboardPage(
    dashboardHeader(),
    dashboardSidebar(uiOutput("choices")),
    dashboardBody()
  )
  
  server &lt;- function(input,output) {
    output$choices &lt;- renderUI(radioButtons("blabla", NULL, 1:100))
  }
  
  shinyApp(ui = ui, server = server)
  </code></pre>
  
  <p>When you run this code, you see that if you scroll down, the nice background on the right hand side suddenly switches to black. How do I make sure that the background stays nice and uniform throughout the entire page, even if a scroll down and use ui-elements?</p>