How to Convert asp.net web application to responsive web page

Hi every one,

I have  asp.net web application. And I use JavaScript and jQuery.

And all the U.I controls are in content place holders like Div, tables.

And this application interacts with sql Server (Backend)

So Now I have a requirement as this to convert to  responsive web page

I have been going through http://materializecss.com/  where all the U.I is divided in 12 partsand based on the device it mapping how many party to display  and so on…..

So now do I need to rewrite all the U.I code or do I need to encapsulate it in some class(rows,columns)

Any leads how to achieve responsive web page.

 So once I make it responsive web page will be work in Mobiles i.e IPhone/Android.

Thank You for all the Help.