Adding transitions to top menu buttons with an animation effect.

The movement is abrupt in the menu buttons of https://test.dfigdesign.com. The CSS3 transition properties can flutter a menu item, making it annoying to the user if they hover over one menu item. Now if you look at https://test.defigdesign.com/citrus which is not running in WordPress it transitions very smoothly. I’m using the same transition-duration , transition-property , and transition-timing-function in both. Is it because WordPress processes this functionality different then doing a non-Wordpress configuration? How should I configure this differently in WordPress to the same smoothness as in the Citrus version, please?
Thanks in advance –