Removing white blank space when side menu is long

My problem is similar to this topic https://athemes.com/forums/topic/search-appearence-and-products-appearence/

But I couldn’t understand how to remove white space when the side menu is too long.

site electronicspanga.com

screenshot: http://prntscr.com/femdbj

Hello ElectronicsPanga,

You can try to group your menu items in submenus to make it shorter.

Please feel free to ask any other questions that you might have.

Kind Regards, Roman.