Show sidebar on mobile w hamburger button


I am new to wordpress and about to build a new site to replace parts of my old one. I would be glad if someone can give me a tips on a plugin to fix a function.

Now when a screen is too small for the sidebar it moves down below the main content. Instead I would like it to hide and show a hamburger button to slide it out like a side panel.
Like at http://www.alternativ.nu

Someone knows how to do this?

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



Source link