title: Using sidebarLayout with fillPage
body: <p>I tried to use <code>sidebarLayout</code> with <code>fillPage</code> in order to fit the plot to full window-size. Below is my attempt but it seems that not working. How could I correct my code to make it work? </p>
  
  <p>Thank you in advance.  </p>
  
  <pre><code>library(plotly)
  if (interactive()) {
    ui &lt;- fillPage(titlePanel("Active in last day"),
                   sidebarLayout(
                     sidebarPanel(
                       dateRangeInput(
                         "date_time_1",
                         "Time",
                         min = '2014-12-01',
                         max = Sys.Date() - 1,
                         start = Sys.Date() - 60,
                         end =  Sys.Date() - 1
                       ),
                       actionButton("btn_download", "Download"),
                       width = 3
                     ),
  
                     # Show a plot of the generated distribution
                     mainPanel(fillRow(
                       plotly::plotlyOutput(
                         outputId = "chart",
                         width = "100%",
                         height = "100%"
                       ),
                       height = "100%"
                     ))
                   ))
  
    server &lt;- function(input, output, session) {
      output$chart &lt;- renderPlotly({
        Animals &lt;- c("giraffes", "orangutans", "monkeys")
        SF_Zoo &lt;- c(20, 14, 23)
        LA_Zoo &lt;- c(12, 18, 29)
        data &lt;- data.frame(Animals, SF_Zoo, LA_Zoo)
        plot_ly(
          data,
          x = ~ Animals,
          y = ~ SF_Zoo,
          type = 'bar',
          name = 'SF Zoo'
        ) %&gt;%
          add_trace(y = ~ LA_Zoo, name = 'LA Zoo') %&gt;%
          layout(yaxis = list(title = 'Count'), barmode = 'group')
      })
    }
    shinyApp(ui, server)
  }
  </code></pre>