body .global-navigation {
  position: fixed; 	// Fix the navigation menu...
  top: 0; 			// ... to the top of the screen
  width: 14em; 		// Make it 14em wide
  left: -14em; 		// And put it just outside the visible window (so that it is initially hidden)
  transition: transform 300ms;// When the menu is 'transformed', animate the transition for a duration of 300 milliseconds
}
body.global-nav-is-open .global-navigation { 	// When the menu is open...
  background: white;							// White background color
  color: #40474d;								// And grey text color
  transform: translate3d(14em, 0, 0); 			// ...move the menu 14em to the right, so that it becomes visible.
  min-height: 0;					// no minimal height, just long enough to contain all menu items 
}