Add a border to conversation heading to add distinction between it and a hilighted post. (TODO: add the same base03-border to all headings for consistency's sake if it looks alright?)

src/components/conversation/conversation.vue

@@ -1,6 +1,6 @@
 <template>
   <div class="timeline panel panel-default base00-background">
-    <div class="panel-heading base01-background base04">
+    <div class="panel-heading base01-background base04 base03-border conversation-heading">
       Conversation
       <span v-if="collapsable" style="float:right;">
         <small><a href="#" @click.prevent="$emit('toggleExpanded')">Collapse</a></small>
@@ -15,3 +15,10 @@
 </template>
 
 <script src="./conversation.js"></script>
+
+<style lang="scss">
+  .conversation-heading {
+    border-bottom-style: solid;
+    border-bottom-width: 1px;
+  }
+</style>