This is just a simple example of Mobile first design coded from scratch. This UI is not beautiful but it is 100% responsive. This is used to display my coding style. I can convert pdf to html. It has been created using Flex property of CSS3. I have also used Jquery for adding some interactivity.
I have some other examples of websites coded by me with a great UI. Check the link below
However, the website code uploaded here is much better but the UI is not that good. Please ignore the UI for this code. Check the responsiveness.