Fix styles in draft version body

There were no elements matching this selector since commit d679c1eb7 and
these styles were completely ignored. I'm re-adding the ones with make
sense in my humble opinion. I'm not adding top and bottom paddings since
they affect the way the height of the element is calculated, and am not
sure about the intention behind setting the height property.

app/assets/stylesheets/admin.scss

@@ -978,17 +978,6 @@ table {
     }
   }
 
-  .legislation-draft-version-body {
-    font-family: $font-family-serif;
-    background: #f5f5f5;
-    height: 16em;
-
-    &:focus {
-      border: 1px solid #cacaca;
-      box-shadow: inset 0 1px 2px rgba(34, 34, 34, 0.1);
-    }
-  }
-
   .markdown-preview {
     font-family: $font-family-serif;
     border: 1px solid #cacaca;
@@ -1032,11 +1021,14 @@ table {
 
     .legislation-draft-version-body {
       border-radius: 0;
-      padding: 1rem;
-      border: 0;
 
       @include breakpoint(medium) {
-        padding: 1rem 2rem;
+        padding-left: 2rem;
+        padding-right: 2rem;
+      }
+
+      &:focus {
+        box-shadow: inset 0 1px 2px rgba(34, 34, 34, 0.1);
       }
     }
 
@@ -1051,12 +1043,6 @@ table {
   }
 }
 
-.legislation-draft-version-body {
-  &:focus {
-    border: 0;
-  }
-}
-
 // 09. Map
 // --------------
 

app/views/admin/legislation/draft_versions/_form.html.erb

@@ -50,7 +50,8 @@
         </div>
 
         <div class="small-12 medium-6 column markdown-area">
-          <%= translations_form.text_area :body, label: false, rows: 10 %>
+          <%= translations_form.text_area :body, label: false, rows: 10,
+                                          class: "legislation-draft-version-body" %>
         </div>
 
         <div class="small-12 medium-6 column markdown-preview">