too large the panel width

I have this website, cbclv.net. When I clicked the top menu, it displayed all submenus below it. However, it doesn’t matter whether it only have submenu or more submenu. the panel width is till the same. is it possible to narrow it such the panel width is appropriate to the number of submnu and looks like. Also, top menu always has its boundary fixed, even when the menu button is smaller than the top menu width. The submenu displayed outside the top menu, and looks a little bit awkward. I am very much appreciated if anyone can help. Thanks in advance.

https://www.ads-software.com/plugins/megamenu/