diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 7c88a8d882..f00f3b780e 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -17,7 +17,7 @@ We only accept issues that are bug reports or feature requests. Bugs must be iso
 
 ## Pull requests
 
-- CSS changes must be done in `.less` files first, never just the compiled `.css` files
+- CSS changes must be done in `.less` files first, never just in the compiled `.css` files
 - If modifying the `.less` files, always recompile and commit the compiled files `bootstrap.css` and `bootstrap.min.css`
 - Try not to pollute your pull request with unintended changes--keep them simple and small
 - Try to share which browsers your code has been tested in before submitting a pull request
diff --git a/_includes/footer.html b/_includes/footer.html
index 7f9f8f103b..56518ac49f 100644
--- a/_includes/footer.html
+++ b/_includes/footer.html
@@ -1,10 +1,9 @@
 <!-- Bootstrap core JavaScript
 ================================================== -->
 <!-- Placed at the end of the document so the pages load faster -->
-<script src="https://code.jquery.com/jquery-1.10.2.min.js"></script>
+<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.10.2/jquery.min.js"></script>
 <script src="{{ page.base_url }}dist/js/bootstrap.js"></script>
 
-<script src="http://platform.twitter.com/widgets.js"></script>
 <script src="{{ page.base_url }}docs-assets/js/holder.js"></script>
 
 <script src="{{ page.base_url }}docs-assets/js/application.js"></script>
@@ -18,6 +17,21 @@
 <script src="{{ page.base_url }}docs-assets/js/customizer.js"></script>
 {% endif %}
 
+{% comment %}
+  Inject Twitter widgets asynchronously. Snippet snipped from Twitter's
+  JS interface site: https://dev.twitter.com/docs/tfw-javascript
+
+  * "js.async=1;" added to add async attribute to the generated script tag.
+{% endcomment %}
+<script>
+  window.twttr = (function (d,s,id) {
+    var t, js, fjs = d.getElementsByTagName(s)[0];
+    if (d.getElementById(id)) return; js=d.createElement(s); js.id=id; js.async=1;
+    js.src="https://platform.twitter.com/widgets.js"; fjs.parentNode.insertBefore(js, fjs);
+    return window.twttr || (t = { _e: [], ready: function(f){ t._e.push(f) } });
+  }(document, "script", "twitter-wjs"));
+</script>
+
 <!-- Analytics
 ================================================== -->
 <script>
diff --git a/examples/offcanvas/offcanvas.css b/examples/offcanvas/offcanvas.css
index 71ad2ac2c4..ef632dc00b 100644
--- a/examples/offcanvas/offcanvas.css
+++ b/examples/offcanvas/offcanvas.css
@@ -2,7 +2,8 @@
  * Style tweaks
  * --------------------------------------------------
  */
-html {
+html,
+body {
   overflow-x: hidden; /* Prevent scroll on narrow devices */
 }
 body {