how to change width of page tabs?

hi – I’m trying to figure out how to change the width of the navigation tabs that point to different pages on my site, so that if I have a name for the page/tab that is a little too long, then the tabs get thrown out of alignment and start stacking oddly and causing other page tabs to shift. I am guessing there is a max char limit for the page tab labels, is there a way to increase the available width or # of characters that could have room on the page tabs. ideas?