improved typekit snippet

_src/_includes/head.html

@@ -58,9 +58,21 @@
         <link rel="stylesheet" href="/assets/css/{{ page.style }}">
     {% endif %}
 
-	<!-- TypeKit -->
-	<script src="//use.typekit.com/msu4qap.js"></script>
-	<script>try{Typekit.load();}catch(e){}</script>
+	<!--
+        TypeKit
+        Improved snippet from https://blog.5apps.com/2014/02/21/using-typekit-the-right-way-with-an-improved-loading-script.html
+    -->
+    <script>
+        (function(d) {
+            var tkTimeout=3000;
+            if(window.sessionStorage){if(sessionStorage.getItem('useTypekit')==='false'){tkTimeout=0;}}
+            var config = {
+                kitId: 'msu4qap',
+                scriptTimeout: tkTimeout
+            },
+            h=d.documentElement,t=setTimeout(function(){h.className=h.className.replace(/\bwf-loading\b/g,"")+"wf-inactive";if(window.sessionStorage){sessionStorage.setItem("useTypekit","false")}},config.scriptTimeout),tk=d.createElement("script"),f=false,s=d.getElementsByTagName("script")[0],a;h.className+="wf-loading";tk.src='//use.typekit.net/'+config.kitId+'.js';tk.async=true;tk.onload=tk.onreadystatechange=function(){a=this.readyState;if(f||a&&a!="complete"&&a!="loaded")return;f=true;clearTimeout(t);try{Typekit.load(config)}catch(e){}};s.parentNode.insertBefore(tk,s)
+        })(document);
+    </script>
 
 	<!-- Picturefill  -->
 	<script src="/assets/js/picturefill.min.js" async></script>