<div class="navigation">
    <input id="navigation-checkbox" type="checkbox">
    <label class="navigation-burger" for="navigation-checkbox">
      <div class="navigation-burger-icon">
        <div class="navigation-burger-icon-bar navigation-burger-icon-bar-top"></div>
        <div class="navigation-burger-icon-bar navigation-burger-icon-bar-bottom"></div>
      </div> <!-- navigation-burger-icon -->
    </label>
    <div class="navigation-background"> </div>
    <ul class="navigation-menu">
      <li class="navigation-menu-item"><a href="#">Item</a></li>
      <li class="navigation-menu-item"><a href="#">Item</a></li>
      <li class="navigation-menu-item"><a href="#">Item</a></li>
      <li class="navigation-menu-item"><a href="#">Item</a></li>
      <li class="navigation-menu-item"><a href="#">Item</a></li>
      <li class="navigation-menu-item"><a href="#">Item</a></li>
      <li class="navigation-menu-item"><a href="#">Item</a></li>
    </ul> <!-- navigation-menu -->
  </div> <!-- navigation -->

  <!--
  Worked derived from:
    Andor Nagy - "Pure CSS Responsive Dropdown Menu" from CodePen &
    Mathieu Lavoie - "Apple style mobile menu" from CodePen.
  -->