MEGAMENU and UPPERCASE

Hi,
My problem :
When I updated Enfold, the menu is shifted to the right (under the menu title).
I solve this problem when I delete this :

.main_menu ul:first-child>li a {text-transform: uppercase;}

But my customer want it in uppercase …

I try to delete my theme child and I have the same problem.
I try to wright directly in uppercase in my menu, …I have the same problem.
I try to shift to the left with css but I have a different result with firefox PC and Firefox MAC …
Please help me.
Thanks