horizontal navbar not working on IE and FIREFOX

dear Forum,
I’m new to word press, and i’ve trying to make my new webpage,
i’ve downloaded “blog-hut-20” theme as a good starting point and have made some changes into it, like the colors and also the navbar. as i was unable to edit the style using wordpress, (keep getting a permissions problem) i’ve been using StyleMaster for editing.
i have tryed several changes until i reached the HORIZONTAL NAV BAR i was looking for, but it would only work on SAFARI, on IE and on FIREFOX i keep getting the vertical navbar.

i would really apreciate if someone can give me a hand with this.

the website is located at:

https://www.noname-magazine.com/index.php

if you woul need to see the stylesheet codes, i have uploaded an .rtf file with the information here:
https://www.noname-magazine.com/stylesheetcode.rtf

i’m sorry if this is a stupid question or if this post has already been treated, i have searched for some answers on the forum but couldn’t find any.

looking forward for some help
cheers,

Johann Velit
MILAN-Italy