change background color of mobile header

I change the default color of the header. The menus on Desktop view looks fine but mobile menu view isn’t. Hope you can help.

https://i.postimg.cc/Vktqd2Nk/woo.png

see the sides are white. I would like the color to be the same for the whole mobile menus.

current code:
.sidebar-menu li{
background-color: #0F2B5B !important;
}

The page I need help with: [log in to see the link]