title: How do I control in SHINY that the HTML background does not show when no output is available
body: <p>After clicking Submit, the output content is correct, but there is a gray background box before the output. If I delete the height in the HTML, there will still be two small arrows, which looks ugly.
  The tag $style is mainly for scrolling through Fasta text, but after that I can't make it disappear without any output, which really bothers me. Please help me, thank you.</p>
  <p><strong>Before submit</strong>
  <a href="https://i.stack.imgur.com/GRfpp.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/GRfpp.png" alt="Before submit" /></a></p>
  <p><strong>Click submit</strong>
  <a href="https://i.stack.imgur.com/vlGSL.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/vlGSL.png" alt="Click submit" /></a></p>
  <pre class="lang-r prettyprint-override"><code>fluidRow(
      column(4, downloadButton(&quot;sequence.txt&quot;, &quot;Download Sequence&quot;, style = &quot;width:100%;&quot;, class = &quot;buttDown&quot;)),
      column(4,downloadButton(&quot;genesequence.txt&quot;, &quot;Download Gene Sequence&quot;, style = &quot;width:100%;&quot;, class = &quot;buttDown&quot;)),
      column(4,downloadButton(&quot;genesinfo.txt&quot;, &quot;Download Gene Information&quot;, style = &quot;width:100%;&quot;, class = &quot;buttDown&quot;))
  ),
            
  textOutput(&quot;seq_title&quot;),
  verbatimTextOutput(&quot;seq&quot;),
  tags$head(tags$style(&quot;#seq_title{color: red;
                                font-size: 22px;
                                font-style: bold;
                              }&quot;
  ),
  tags$style(&quot;#seq{
              width = 100%;
              padding: 6px 12px;
              white-space: pre-wrap;
            height: 300px;
  }&quot;)
  ),
  textOutput(&quot;cds_title&quot;),
  verbatimTextOutput(&quot;cds&quot;),
  tags$head(tags$style(&quot;#cds_title{color: red;
                                font-size: 22px;
                                font-style: bold;
                              }&quot;
  ),
  tags$style(&quot;#cds{
              width = 100%;
              padding: 6px 12px;
              white-space: pre-wrap;
  }&quot;)
  ),
  textOutput(&quot;pro_title&quot;),
  shiny::verbatimTextOutput(&quot;pro&quot;),
  tags$head(tags$style(&quot;#pro_title{color: red;
                                font-size: 22px;
                                font-style: bold;
                              }&quot;
  ),
  tags$style(&quot;#pro{
              width = 100%;
              padding: 6px 12px;
              white-space: pre-wrap;
              display:block;
              
  }&quot;)
  ),
  DT::dataTableOutput(&quot;geneinfo&quot;),
  
  textOutput(&quot;genetitle&quot;),
  verbatimTextOutput(&quot;searchgenesequence&quot;),
  tags$head(tags$style(&quot;#genetitle{color: red;
                                font-size: 22px;
                                font-style: bold;
                              }&quot;
  ),
  tags$style(&quot;#searchgenesequence{
              width = 100%;
              padding: 6px 12px;
              white-space: pre-wrap;
  }&quot;)
  )
  </code></pre>