[Plugin: Fast and Secure Contact Form] How to have border around final message

How can I add a blue border around the final message (i.e. “your email was sent successfully”), similar to that of Contact Form 7.

This way, the sender immediately sees the message and not hunt for it.

Thanks

P.S. I switched to Fast And Secure Form as Contact Form 7’s latest update seems to have lost the ability to send email to me, which is a very critical part of any website. No time to debug, best to change to another good one 🙂