Fixed Width Menu Items

Hello all,

I’m attempting to code my own WordPress Theme and am having issue with setting a top menu with fixed-width menu items. I have background images at 113px wide, but the menu items are varied depending on the text name.

If you look at my site, https://deepseaengine.com you can see that the menu images are clipped for all menu items except the longest one, projects. How can I code a fixed-width of 115px in CSS to all menu items (which will hopefully solve the background image clipping)?

Any help would be hugely appreciated!