Use dividers instead of border on <section>

tildes/scss/_base.scss

@@ -182,8 +182,6 @@ pre {
 
 section {
   margin-top: 1rem;
-  padding-top: 1rem;
-  border-top: 2px solid;
 }
 
 summary {

tildes/scss/themes/_theme_base.scss

@@ -90,10 +90,6 @@
     background-color: map-get($theme, "background-primary");
   }
 
-  section {
-    border-color: map-get($theme, "border");
-  }
-
   tbody tr:nth-of-type(2n + 1) {
     background-color: map-get($theme, "background-secondary");
   }

tildes/tildes/templates/message_conversation.jinja2

@@ -18,6 +18,7 @@
   {% endfor %}
 
   <section>
+    <div class="divider"></div>
     <h2>Add a new reply to this conversation</h2>
     <form
       method="post"

tildes/tildes/templates/topic.jinja2

@@ -168,6 +168,7 @@
 
 <section class="topic-comments">
   {% if comments %}
+    <div class="divider"></div>
     <header class="topic-comments-header">
       <h2>{{ pluralize(topic.num_comments, "comment") }}</h2>
 
@@ -215,6 +216,7 @@
 
 {% if request.has_permission('comment', topic) %}
   <section data-js-remove-on-success>
+    <div class="divider"></div>
     <h2>Post a comment</h2>
     <form
       method="post"