Add CSS styling to a button in Wordpress- Hiring today, finish today, get paid today!

Hi! Looking for a wordpress developer who is experienced with CSS/PHP. I have a button that I am trying to style (I'm not familar with wordpress/php). I have the line of code the button is on in PHP, but I'm not sure how to link that to a CSS and give the button style (size, color, font color, and a shadow). I have the color and size I would like for it to take. I would like for someone to connect a style to this button today. I would like to finish the project in the next few hours. If you can start now, I can pay you immediately after. I've attached the current look of the button, and the CSS I would like to add is below: <input type="submit" name="rcp_submit_registration" id="rcp_submit" value="SIGN UP" style=" padding-left: 70px; padding-right: 70px; padding-top: 20px; padding-bottom: 20px; background-color: #4CAF50; /* Green */ border: none; color: white; font-size: 22px;"> Please reply with "I have read this" somewhere in your response so I know you've taken a look.