CMS Made Simple Forums

Sorry to bother you but I have this little/big problem with my css and menu.
First, I have not much experience in codes.
I have successfully create or a custom template by copying the css into newly created css in my CMSMS admin panel, same with the template now everything works fine except the menu.
In the template i copied there is this css effect were if i click a menu the color of the current menu text will be different from the other menu. But in my CMSMS site, the effect is not working.
I am using the latest version of CMSMS with only core modules.

I would appreciate all assistance.
Thanks a lot.

This is not something that can be solved with out a link to the site and a link to a working example, I would change the CSS to use the classes etc. that come with one of the default menu templates...