checkout cart - css problems on mobile devices

-- url of the page with the problem -- : stattgarde.de/index.php/duty-free-shop/checkout
-- HikaShop version -- : 3.1.1
-- Joomla version -- : 3.6.5
-- PHP version -- : 5.6.30

Hi!

I do have a CSS problem with the checkout cart. Everything is fine except the diplay fo the subtotal, tax, shipping fee etc. I enclosed a screenshot. In the normal use it is not that problem - bit using a mobile device it looks terrible. (second screenshot)

The problem is that I was not successful in finding the right line to change that. It was only possible for me to chance the text-align of the whole table

Might anyone give little support to change the marked line into the way it looks better?

Thanks so much for any kind of support.

Greetings from Cologne, Germany

Frank