css target one specific item

Hi ?? thanks in advance for any help you can bring me

this is my site https://lalulula.tv/

I am trying to achieve 2 columns dropdown by this method https://www.prowebdesign.ro/wordpress-sub-menu-items-split-in-2-columns-the-easy-way/

BUT i need to use it in just some of the menu itemns, not all of them, so I am tryning to change the UL with of just one of the menu items by doing this:

#menu-item-9154 #cb-nav-bar #cb-main-menu .main-nav li .cb-links-menu .cb-sub-menu {width: 400px !important;}

but i’ts not working….
any ideas how can I do it?

thanks so much!