Update style and templates

For signature.

app/templates/pm/topic.forkbb.php

@@ -103,7 +103,9 @@
           </div>
         @if ($p->user->showSignature && $post->user->isSignature)
           <aside class="f-post-sign">
-            <hr class="f-sign-brd">
+            <div class="f-sign-brd">
+              <small>- - -</small>
+            </div>
             {!! $post->user->htmlSign !!}
           </aside>
         @endif

app/templates/topic.forkbb.php

@@ -117,7 +117,9 @@
           </div>
         @if ($p->user->showSignature && $post->user->isSignature)
           <aside class="f-post-sign">
-            <hr class="f-sign-brd">
+            <div class="f-sign-brd">
+              <small>- - -</small>
+            </div>
             {!! $post->user->htmlSign !!}
           </aside>
         @endif

public/style/ForkBB/style.css

@@ -1557,7 +1557,9 @@ body,
 }
 
 #fork .f-sign-brd {
-  margin: 0;
+  width: 50%;
+  border-top-width: 0.0625rem;
+  border-style: dashed;
 }
 
 #fork .f-admin-note {