handle the swanky navigation/section stuff

gistfile1.js

// http://speckyboy.com/2014/06/25/content-overlays-css3-transitions/

(function(){
  
  // handle the swanky navigation/section stuff
  ////////////////////////////////////////////////////////////
  
  var nav_links = document.querySelectorAll("nav.cmn-overlays-nav a");
     
  /* loop through all nav links */
  [].slice.call(nav_links).forEach(function(el, i) {
     
    /* fetch vars */
    var href = el.getAttribute("href"),
        id = href.substr(1),
        section = document.querySelector(href),
        close = section.querySelector("a.close");
  
    /* listen for nav clicks */
    el.addEventListener("click", function(e) {
      e.preventDefault();
      if (!classie.has(section, "active")) {
        classie.add(section, "active");
      }
    });
  
    /* listen for close clicks on the mask */
    section.addEventListener("click", function(e) {
      e.preventDefault();
      if (e.target.tagName == "SECTION") {
        if (classie.has(section, "active")) {
          classie.remove(section, "active");
        }
      }
    });
  
    /* listen for close clicks on the close button */
    close.addEventListener("click", function(e) {
      e.preventDefault();
      if (classie.has(section, "active")) {
        classie.remove(section, "active");
      }
    });
  
  });
  
})();