FancyNav.txt

// Sass
#Menu-button
  display: none
  &:checked ~ #Menu-wrapper
    display: block
 
#Menu-label
  display: block
  text-align: center
  font-size: 1.5em
      
#Menu-wrapper
  display: none

@media screen and (min-width: 640px)
  #Menu-label
    display: none
        
  #Menu-wrapper
    display: block

// Html

<input id="Menu-button" type="checkbox" />
<label for="Menu-button" id="Menu-label" data-icon="menu" onclick></label>
<nav id="Menu-wrapper">
	<ul>
		...
	</ul>
</nav>