Why not make your life easier and try out Bootstrap?
Then you get the mobile responsive design from start.
Bootstrap 3 Tutorial[
^]
Personally I will not try to fix your code. It is way too much work.
Maybe someone else will.
[UPDATE]
To make a design that is responsive you need to get the size of the screen, which you have done, but also consider the with of the current browser.
In my case I have a wide screen on my laptop and if I open your website and make the browser smaller the content does not follow the size of the window, but stays aligned according the size of the screen.
If you fix this issue, I think you will have a better result for mobile screens too.
Am I going to go through all your code and fix it for you?.
Nope, you don't pay enough. -:)
The reason why you get advice to use Bootstrap is because all this is already considered and you can focus on the content instead of the layout details.
Bootstrap is not that difficult to learn and you can copy most of your existing HTML into a
<div class="container">
<div class="row">
<div class="col-sm-2"></div>
<div class="col-sm-8">
<!--
</div>
<div class="col-sm-2"></div>
</div>
</div>
providing you have imported the Bootstrap scripts and styles.