title: Removing White Space between Shiny Dashboard Header and Leaflet Map
body: <p>I have a Shiny app that displays a leaflet map.  I am trying to remove white space between the Shiny dashboard header and the map.  I also want to remove white space on the side margins.  I suspect that doing this requires modifying margins or padding through CSS but I have not found the solution.</p>
  
  <p>Here's the code for a simplified version of my app -      </p>
  
  <pre><code>```{r}
  ui &lt;- navbarPage("Example Page", id = "nav",
         tabPanel("Some Header",
                  tags$style(type = "text/css", "#map {height: 
                  calc(100vh - 70px) !important;}"), 
                    leafletOutput("map")))
  
  server &lt;- function(input, output, session) {
               output$map &lt;- renderLeaflet({
              leaflet() %&gt;%
              addTiles() %&gt;% 
              setView(lng = -93.85, lat = 37.45, zoom = 5)})
  }
  
  shinyApp(ui, server)
  
  ```
  </code></pre>
  
  <p>Here's an image of the resulting app.  I want to know how I can modify this code to remove all whitespace.</p>
  
  <p>Example_App</p>
  
  <p><a href="https://i.stack.imgur.com/pZNxg.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/pZNxg.jpg" alt="enter image description here"></a></p>