Drop down menus out of alignment after upgrade.

Hi Just upgraded to the latest version of Catch Kathmandu Pro 5.2.5 and the page size no longer filled the screen so added the following into Additional CSS - .site { width: 100%; margin: auto; } That worked OK but and the menu is where I want it but the dropdown menu boxes don't line up, looks like they are all over to the left. The text is OK and appears to be right aligned within the box. Can't figure out what's missing to correct this? https://holthouse.sheffield.sch.uk/ Many thanks