Hi, I have downloaded the code you have attached and run it as a HTML on browser. I can work on your given template and make sure to be 100% responsive on all screens and also will be in single file as per your ebay requirement. I can work with you right now. Consider me.
I am Front End UI Developer, having expertise in Web 2.0 technologies - HTML5, CSS3, JavaScript, jQuery, and Js frameworks (Angular 4). I have worked with Bootstrap 3 and 4 for design purposes building responsive web applications. I also have good expertise in CSS Pre-Processors: SASS, LESS and Stylus.
Thanks