Get rid of jQuery \o/

source/index.html.haml

@@ -17,7 +17,7 @@ cover_license: '[Cover Image](https://unsplash.com/photos/2ShvY8Lf6l0) by [Lukas
         %span= "by #{link_to blog_author.name, author_path}"
         = partial(:profile_links, locals: {author: blog_author.name})
 
-  %a.scroll-down.icon-arrow-left{href: '#content', data: {offset: '-45'}}
+  %a.scroll-down.icon-arrow-left{href: '#content', data: {offset: '45'}}
     %span.hidden Scroll Down
 
 %main#content.content{role: :main}

source/javascripts/application.js

@@ -0,0 +1,2 @@
+#= require casper
+#= require obfuscate

source/javascripts/application.js.coffee

@@ -1,3 +0,0 @@
-#= require vendor/jquery-1.12.0
-#= require vendor/casper
-#= require obfuscate

source/javascripts/casper.js

@@ -0,0 +1,101 @@
+(function() {
+  document.addEventListener('DOMContentLoaded', function() {
+    document.querySelectorAll('.menu-button, .nav-cover, .nav-close').forEach(function(element) {
+      element.addEventListener('click', function(event) {
+        event.preventDefault();
+
+        var body_classes = document.body.className.split(' ');
+        ["nav-opened", "nav-closed"].forEach(function(klass){
+          var i = body_classes.indexOf(klass);
+          i >= 0 ? body_classes.splice(i, 1) : body_classes.push(klass);
+        });
+        document.body.className = body_classes.join(' ');
+      });
+    });
+  }, false);
+
+  // slightly adapted from http://stackoverflow.com/a/26798337/421705
+  window.requestAnimFrame = (function(){
+    return  window.requestAnimationFrame       ||
+            window.webkitRequestAnimationFrame ||
+            window.mozRequestAnimationFrame    ||
+            function( callback ){
+              window.setTimeout(callback, 1000 / 60);
+            };
+  })();
+
+  function scrollToY(scrollTargetY, speed, easing) {
+    // scrollTargetY: the target scrollY property of the window
+    // speed: time in pixels per second
+    // easing: easing equation to use
+
+    var scrollY = window.scrollY,
+        scrollTargetY = scrollTargetY || 0,
+        speed = speed || 2000,
+        easing = easing || 'easeOutSine',
+        currentTime = 0;
+
+    // min time .1, max time .8 seconds
+    var time = Math.max(.1, Math.min(Math.abs(scrollY - scrollTargetY) / speed, .8));
+
+    // easing equations from https://github.com/danro/easing-js/blob/master/easing.js
+    var PI_D2 = Math.PI / 2,
+        easingEquations = {
+          easeOutSine: function (pos) {
+            return Math.sin(pos * (Math.PI / 2));
+          },
+          easeInOutSine: function (pos) {
+            return (-0.5 * (Math.cos(Math.PI * pos) - 1));
+          },
+          easeInOutQuint: function (pos) {
+            if ((pos /= 0.5) < 1) {
+              return 0.5 * Math.pow(pos, 5);
+            }
+            return 0.5 * (Math.pow((pos - 2), 5) + 2);
+          }
+        };
+
+    // add animation loop
+    function tick() {
+      currentTime += 1 / 60;
+
+      var p = currentTime / time;
+      var t = easingEquations[easing](p);
+
+      if (p < 1) {
+        requestAnimFrame(tick);
+        window.scrollTo(0, scrollY + ((scrollTargetY - scrollY) * t));
+      } else {
+        window.scrollTo(0, scrollTargetY);
+      }
+    }
+
+    // call it once to get started
+    tick();
+  }
+
+  document.addEventListener('DOMContentLoaded', function() {
+    document.querySelectorAll('.scroll-down').forEach(function(element) {
+      element.addEventListener('click', function(event) {
+        event.preventDefault();
+
+        var speed = 500,
+            offset = this.getAttribute('data-offset') ? this.getAttribute('data-offset') : false,
+            position = this.getAttribute('data-position') ? this.getAttribute('data-position') : false,
+            toMove;
+
+        var elementBottom = this.getBoundingClientRect().bottom + window.pageYOffset - (document.clientTop || 0);
+
+        if (offset) {
+          toMove = parseInt(offset);
+          scrollToY(elementBottom + toMove, speed, 'easeInOutQuint')
+        } else if (position) {
+          toMove = parseInt(position);
+          scrollToY(toMove, speed, 'easeInOutQuint')
+        } else {
+          scrollToY(elementBottom, speed, 'easeInOutQuint')
+        }
+      });
+    });
+  }, false);
+})();

source/javascripts/obfuscate.js

@@ -30,4 +30,4 @@
       element.innerHTML = link;
     });
   }, false);
-})()
+})();