title: Cannot find which css style is being applied to an element
body: <p>In the following screenshot, some of the css style (red border) is being applied to the input fields to indicate the error. However I am unable to figure out which css selector it is, Firebug does not display any style being applied.</p>
  
  <p><a href="https://i.stack.imgur.com/ldEFu.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/ldEFu.png" alt="enter image description here"></a></p>
  
  <p><strong>Demo:</strong>
  Sorry, there is no direct URL for the page, here's how you can see that:</p>
  
  <ol>
  <li>Go here: <a href="https://wordpress.org/themes/imgwize/" rel="nofollow noreferrer">https://wordpress.org/themes/imgwize/</a></li>
  <li>Click on "Preview" button.</li>
  <li>Scroll down the page and click on the first post "Hello world". You can see the comment form there.</li>
  <li>Leave the fields empty and click on Post comment button.</li>
  </ol>