Add a sticky header button to existing Wordpress Website

I am looking for someone to add a 'sticky' 'ORDER NOW!' button to my existing WordPress website. Technical Requirements: - Background Colour to use: #6E942E - Font Colour to use: 'white' - on hover 'black' - Font to use (same as website body) Open Sans, Capitals, Thick and obvious. (Your judgement can be used here) - To only display on the Home Page, i.e. not on sub pages e.g. /order *worth noting that this is a 1 page home page (with multiple sections) - To be visible on mobile/tablet & desktop devices. Button Height (fixed at 50px) obviously the width would change depending on the device - Text to be centred - And css etc to be added in existing child theme so that updates don't cause problems - Button to link to [login to view URL] For further info please get in touch! The website is currently private so I will provide login details. Theme I'm using is ThemeX and has a customiser with custom css input. Please refer to screen shots to get a bit of an idea (i have used the theme's top-bar as a bit of an idea.) I can't see this project taking any longer than 1 hour (tops) therefor my budget is $10USD-$15USD