CSS Design Fixes / Update and Responsive Fixes

I require an individual that support in updating some design changes in CSS on a WordPress site. I will also need changes to responsive elements. Individual will also need to check cross browser compatibility and address any major CSS code issues ( not minor issues)

Summary :

Number of pages to update in CSS Design 5/6
Update of page / post template 5/6
Responsive check = 15 / 20 pages

I will need to be able to speak to individual and have 1 to 1 session to work through requirements which are documented.

Expected hours to complete work 10 - 15.

Thanks