title: label doesn't display when hover
body: <p>hi I want the label "hidden-btn-txt" display when hover
  but It doesnt show at all when the mouse is on the label
  i tried to do hover to the "hidden-btn" but it doesnt work</p>
  
  <p><strong>html in tsx:</strong></p>
  
  <pre><code>  return (&lt;ul className='tickets'&gt;*
              {filteredTickets.map((ticket) =&gt; (&lt;li key={ticket.id} className='ticket'&gt;
                  &lt;div className="hidden-btn" onClick={this.onHide.bind(this, ticket.id)} &gt;
                      &lt;label id="hidden-btn-txt"&gt;Hide&lt;/label&gt;
                  &lt;/div&gt;
                  &lt;h5 className='title'&gt;{ticket.title}&lt;/h5&gt;
                  &lt;p className='content'&gt;{ticket.content}&lt;/p&gt;
                  &lt;footer&gt;
                      &lt;div className='meta-data'&gt; &lt;span&gt; By {ticket.userEmail} | { new Date(ticket.creationTime).toLocaleString()}&lt;/span&gt;
                          {ticket.labels ? this.renderLabels(ticket.labels): null}
                      &lt;/div&gt;
                  &lt;/footer&gt;
              &lt;/li&gt;))}
          &lt;/ul&gt;);
  
  
  </code></pre>
  
  <p><strong>css:</strong></p>
  
  <pre><code> .ticket {
              width: 100%;
              flex-shrink: 0;
              border-radius: 8px;
              background-color: #fff;
              box-shadow: 0 2px 6px 1px #e1e5e8;
              margin-bottom: 14px;
              display: flex;
              flex-direction: column;
              border: 1px solid #fff;
              padding: 10px 20px;
              transition: box-shadow .2s ease-in-out;
              position: relative;
  
              &amp;:hover {
                  box-shadow: 0 2px 6px 1px #d3d7da;
              }
              #hidden-btn-txt{
                  display: inline-block;
                  color:  #20455e;
                  font-size: 12px;
                  font-style: normal;
                  text-align: right;
                  float: right;
  
              }
              #hidden-btn-txt.hover{
                  display: inline-block;
              }
  </code></pre>