Create CSS to make older web pages mobile-friendly

My website uses older code (html and css style sheets, and a few java scripts). I did some research and found that there are three ways to make a site mobile-friendly. [login to view URL] The first one "responsive" is described as follows: "Responsive: the page - URL, HTML, images, everything - remains the same, but the CSS gives different rules based on browser width." This seems to be the simplest way to go. I can install the CSS codes myself once you have it prepared This is not an app. Just CSS code to convert my website to a more mobile friendly one. Your job is to find a CSS code, test it on your cell phone and desktop browser, and once you see it works, send it to me. I have posted projects in the past that got bids in the thousands of dollars, but were completed for just a few bucks. Here is the URL to a sample page: [login to view URL]