How to position the close (×) button on the top-right of a flash message in my web app?

I’m using Flash to display messages on my web application, and I want the close (×) button to be positioned in the top-right corner of the flash message. Currently, it appears slightly misaligned for error messages, while it works fine for success messages.

req.flash(‘success’, ‘you must be signed in’)
req.flash(‘error’, ‘you must be signed in’)
I was expecting the cross sign in the error message to be on the same position as of the success message