[E] Responsive website
Here is an exercise that helps you enable mobile responsivness on your website.
The exercise "Responsive website with header, navbar and footer"
Figure. This is how the responsive example looks like when its done.
The exercise "Responsive website with header, navbar and footer" shows how to build the page structure you need with column layout and how to make a responsive website.
Work through it and make the code to "your own code".