I would like to customize a shiny application using `tabsetPanels` so that the selected panel appears in a black background with white text, and the unselected tabs show a white background with black text.

For example, In the application below, when the "Hello" tab is selected, I would like "Hello" to be in white text on a black background. But I still want the background of the panel content (the input field) to remain white.

The closest thing I've been able to find come from this question: [Tab Box CSS for shinydashboard](https://stackoverflow.com/questions/32233477/tab-box-css-for-shinydashboard)

Applying that code yields a colored background all the way across the tabsetPanel, but I still can't find a way to modify this to change the background of only the tabs. Furthermore, nothing I change in the `.nav-tabs-custom` css seems to take any effect whatsoever.

I'm continually tempted to try applying changes to the `tab-pane` tag CSS, but that pushes changes into the body of the tab, not the title box.

Any ideas on what I could change to get the title boxes to change background color?

```
ui <- shinyUI(
  fluidPage(
    tags$style(".nav-tabs {
  background-color: #006747;
    }

.nav-tabs-custom .nav-tabs li.active:hover a, .nav-tabs-custom .nav-tabs li.active a {
background-color: transparent;
border-color: transparent;
}

.nav-tabs-custom .nav-tabs li.active {
    border-top-color: #FFF;
}"),
    tabsetPanel(
      tabPanel(
        title = "Hello",
        textInput(inputId = "text", label = "Input")
      ),
      tabPanel(
        title = "World"
      )
    )
  )
)

server <- shinyServer(function(input, output, session){

})

shinyApp(ui=ui, server=server)

```