responsive width scratching

Hi,

Sorry it maybe just me, I have tried the responsive css, it was working fine in my other website, but in my new site it looks scratching, I tried many ways playing with the css, but I just can’t find it.
Please see the site on the refference and click on redeem, a popup with signature field will come and asa you can try to sign it will scratching..

Appreciate for any help..

Regards,
Surya

The page I need help with: [log in to see the link]