title: Reactjs - how to change styling of inputValidator of sweetalert2 popup
body: <p>I'm currently using sweetalert2 to have the user select a file.  If the user does not select a file I am using inputValidator to post an error message on the popup.  The default error message puts a red border around the file input box.  Is it possible to remove the red border or to customize it (change it to green/blue)?  Here is the code I am using.</p>
  <pre><code>const MySwal = withReactContent(Swal)
  
      MySwal.fire({
          confirmButtonText: 'Submit File',
          showCancelButton: true,
          title: &quot;&lt;b&gt;Submit New File&lt;/b&gt;&quot;,
          input: 'file',
          focusConfirm: false,
          allowOutsideClick: false,
          inputValidator: (value) =&gt; {
            if(!value){
              return &quot;Please select a file&quot;
            }
          }
  </code></pre>
  <p>Thanks!</p>
  <p><a href="https://i.stack.imgur.com/22srI.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/22srI.jpg" alt="enter image description here" /></a></p>