how to arrange a menu in single line..

I have changed the following code on line 81 of my 2011 child theme

#access div {
	margin: 0 4.5%;

after doing this my menu is now in a single line but when i click last 3 tabs, the last tab now moves to the second line..how to troubleshoot that?here is the link to my site https://www.kutchtheheaven.info/
thank you.