Wrap all page content in #main div to fix #86

- Adjust article styles to correctly display post indexes
- Remove top margin from page titles

_layouts/post.html

@@ -32,7 +32,7 @@
   <div class="article-author-side">
     {% include _author-bio.html %}
   </div>
-  <article>
+  <article class="post">
     <div class="headline-wrap">
       {% if page.link %}
         <h1><a href="{{ page.link }}">{{ page.title }}</a></h1>