css: clean up various unnecessary css.

app/views/artists/_show.html.erb

@@ -13,11 +13,11 @@
     <%= yield %>
 
     <div class="recent-posts">
-      <h1>Recent Posts</h1>
+      <h2>Recent Posts</h2>
 
       <%= render "posts/partials/common/inline_blacklist" %>
 
-      <div style="margin: 1em 0;">
+      <div>
         <%= @post_set.presenter.post_previews_html(self) %>
       </div>
     </div>

app/views/artists/_summary.html.erb

@@ -14,7 +14,7 @@
     <% end %>
     <% if artist.domains.any? %>
       <li><strong>Domains</strong></li>
-      <ul>
+      <ul class="list-bulleted">
         <% artist.domains.each do |url, count| %>
           <li><%= url %>: <%= count %></li>
         <% end %>