Use this pure CSS hamburger menu in your next project where you want to show a full-screen navigation menu. It was designed by Julien Lejeune. When you click on the menu icon on the top right it slides out the navigation menu that fills up the entire screen and turns the hamburger menu to an X. Clicking on the X will close the navigation menu and resurface the content.
If you are having trouble with the pen, try the archived copy on GitHub
See the Pen Burger Menu – Full CSS / No JS by Julien Lejeune (@jlnljn) on CodePen.0