Menu format lost after latest update

Hello there,
After the latest Evolve update, my menu suddenly no longer fits on one line. The padding before the update was set at 5, but I have now had to reduce it down to 1 to allow it to fit on a line as it did before. This seems to have now reduced the size of the sub-fonts.
Any advice on this is gratefully received. I have cleared all cache and refreshed the browser many times.
My url is http://www.thoughtboxeducation.com
Many thanks,
Rachel