Want to turn off floating social icons for small sizes

Hi - I want to turn off floating social icons for smaller displays. I tried putting
#wdsb-share-box { display: none; }
in the relevant media query in style.css but it had no effect.

On the live site
http://amfinefurniture.co.uk/bespoke-furniture/elm-dining-table/
I successfully turn off (make noshow) the current social icon bar I am using, but it doesn't seem to work when I try to do the same thing with your plugin.

Any ideas?