title: Clean Up Select Form in Shiny Application with ShinyWidgets and bslib
body: <p>The following code can be used to reproduce my issue and help illustrate my question. When using the <a href="https://bootswatch.com/litera/" rel="nofollow noreferrer">litera</a> theme, box 2 in the UI renders somewhat &quot;ugly&quot; on screen. You can see in this that box 2 has a little bit of white edge on the corner.</p>
  <p>I prefer the functionality of box 2 from ShinyWidgets (especially for multiple select), but only if I can get it to look a bit more professional. This seems to be theme-specific. If I change theme to &quot;flatly&quot; both forms look nice.</p>
  <p>Also, the browse button with this theme doesn't seem to quite be lined up with its input box.</p>
  <p>My two questions then are: 1) Does anyone know how to remove that little bit of color inside box 2 so it is white and renders more like box1? Second, any suggestions on how to clean up the browse so it lines up a bit more and looks cleaner?</p>
  <pre><code>library(shiny)
  library(bslib)
  library(shinyWidgets)
  
  ui &lt;- fluidPage(
      navbarPage(
          theme = bs_theme(bootswatch = &quot;litera&quot;),
          title = 'Methods',
          tabPanel('One'),
      ),  
      sidebarLayout(
          sidebarPanel(
              fileInput('input0', 'Browse'),
              uiOutput(&quot;input1&quot;),
              uiOutput(&quot;input2&quot;)
          ),
          mainPanel(
              h1('Hello World!'),
          ),
      )
  )
  
  server &lt;- function(input, output) {
  output$input1 &lt;- renderUI({
      selectInput(&quot;input1&quot;, &quot;Choose:&quot;, letters[1:5])
  })
  
  output$input2 &lt;- renderUI({
      pickerInput(&quot;input2&quot;, &quot;Choose:&quot;, letters[1:5])
  })
  
  }
  
  shinyApp(ui, server)
  </code></pre>