Der Tor:1428926826 wrote
I know that the vector template is designed to work on mobile devices
It is most definitely *not* designed to work on mobile devices.
It is not that bad because of the flexibility of the main content area. But there is not a single piece of code in Vector which makes the template responsive. Wikipedia itself is not responsive either (on mobile devices they load a different template), see also
http://www.mediawiki.org/wiki/Manual:Mobiles,_tablets_and_responsive_design. And as Vector is based on the Wikipedia template, it also inherits the missing responsiveness.
On the one hand you could ask the template author to optimise the template for mobile devices, on the other hand it is probably best to make that request to the original Vector skin authors. But then again, I am pretty sure lots of people already made that request, so unfortunately it's unlikely to lead to anything. :-(
Alternatively you could use the
LoadSkin plugin to load a different and optimised template on mobile devices.