如何在移动汉堡包菜单中心并防止单击菜单项时我的菜单消失？

I want that my mobile hamburger menu and submenu items are centered, and that when I click on one of the menu items that contain a subemenu item, it won't disappear. I've tried different things in CSS but I can't seem to solve this by myself.I want that my mobile hamburger menu and submen