Mobile website layout

Dear all,

currently my coupon website shows a single long row of icons when i visit it from a mobile device or a very small browser window.

How can I change this single row into showing possibly 2 or 3 vertical rows of icons next to each other? I have some css skills I just don’t know how to do this so any hints would be appreciated.

Please take a look a the attached image for example:

Website url: VoucherAlarm

Thank you in advance!

With kind regards