Make website responsive and clean out unnecessary code

I have five pages of HTML and an associated CSS file. These are not hosted, so can be sent as-is. Currently these pages display well on a PC, but do do not respond to screen resizing for mobile phone. These files also contain material that is no longer used and so should be edited out as part of a general cleaning up of the site. This project is about editing this existing code - Wordpress and similar tools are not required.

As the code may be used later for other sites, it should be properly documented.

In synopsis, the project is to make the code responsive to various screen sizes and to clean it up of extraneous material and to document it.