Preference Centre: How to change css to be mobile friendly

Your software
My Mautic version is: V2. 16. 01
My PHP version is: 7.0.33-26

Your problem
I have my preference centre in a theme that is mobile friendly. However the slots types, that I can drag and drop into the preference centre landing page, is not suited to mobile devices.
Is there a way to change the css of the ‘slot types’, in particular ‘segmentlist’ and channelfrequency’, so that it is mobile friendly?

Any advice would be appreciated.