Wordpress Responsive HTML5 and CSS3

I need a worker with excellent skills in using HTML5 and CSS3 for wordpress responsive sites.

Some of the work will be taking existing premium themes and changing them to suit us.

And some of the work will be developing a responsive theme from the beginning, doing all the coding.

To start with this is a part-time job, about 10-15 hours per week and may become full-time later if you want.

In your application, please tell me why you are the best for this job and examples of the work you can do.