diff --git a/core/modules/system/css/system.module.css b/core/modules/system/css/system.module.css
index 0ade513..010f618 100644
--- a/core/modules/system/css/system.module.css
+++ b/core/modules/system/css/system.module.css
@@ -142,19 +142,18 @@ a.tabledrag-handle:focus .handle {
   margin: -0.4em -0.4em -0.4em 0.2em;
   padding: 0.42em 0.6em 0.42em 0;
 }
-.tree-child {
+.tree-child,
+.tree-child-horizontal {
   background: url(../../../misc/tree.png) no-repeat 11px center; /* LTR */
 }
 .tree-child-last {
   background: url(../../../misc/tree-bottom.png) no-repeat 11px center; /* LTR */
 }
 [dir="rtl"] .tree-child,
+[dir="rtl"] .tree-child-horizontal,
 [dir="rtl"] .tree-child-last {
   background-position: -65px center;
 }
-.tree-child-horizontal {
-  background: url(../../../misc/tree.png) no-repeat -11px center;
-}
 .tabledrag-toggle-weight-wrapper {
   text-align: right; /* LTR */
 }
@@ -184,6 +183,7 @@ a.tabledrag-handle:focus .handle {
 }
 .progress__track {
   background-color: #fff;
+  box-sizing: border-box;
   border: 1px solid;
   margin-top: 5px;
   max-width: 100%;
@@ -255,14 +255,11 @@ tr .ajax-progress-throbber .throbber {
   top: 48.5%;
   z-index: 1000;
   background-color: #232323;
-  background-image: url("../../../misc/loading-small.gif");
-  background-position: center center;
-  background-repeat: no-repeat;
+  background: url(../../../misc/loading-small.gif) no-repeat center center;
   border-radius: 7px;
-  height: 24px;
   opacity: 0.9;
-  padding: 4px;
-  width: 24px;
+  height: 32px;
+  width: 32px;
 }
 
 /**