diff --git a/gtk/theme/HighContrast/_common.scss b/gtk/theme/HighContrast/_common.scss
index 9da926f72c..29c172fc06 100644
--- a/gtk/theme/HighContrast/_common.scss
+++ b/gtk/theme/HighContrast/_common.scss
@@ -2262,20 +2262,37 @@ stacksidebar {
 
 
 paned {
-  // This is actually the invisible area of the paned separator, not a margin...
-  margin: 0 8px 8px 0; //drag area of the separator
-  &:dir(rtl) {
-    margin-right: 0;
-    margin-left: 8px;
-  }
   separator {
-    //FIXME abusing a background-image to get rid of the handle decoration
-    //I'd like something better...
+    min-width: 1px;
+    min-height: 1px;
     background-image: linear-gradient(to bottom, $borders_color);
     &:backdrop {
       background-image: linear-gradient(to bottom, $backdrop_borders_color);
     }
   }
+   &:dir(ltr).horizontal separator {
+    margin: 0 -8px 0 0;
+    padding: 0 8px 0 0;
+  }
+  &:dir(rtl).horizontal separator {
+    margin: 0 0 0 -8px;
+    padding: 0 0 0 8px;
+  }
+  &.vertical separator {
+    margin: 0 0 -8px 0;
+    padding: 0 0 8px 0;
+  }
+  separator:selected {
+    background-color: $selected_bg_color;
+  }
+  separator.wide {
+    min-width: 5px;
+    min-height: 5px;
+    background-color: transparent;
+    border-style: none solid;
+    border-color: $borders_color;
+    border-width: 1px;
+  }
 }
 
 paned.wide { // this is for the paned with wide separator
diff --git a/gtk/theme/HighContrast/gtk.css b/gtk/theme/HighContrast/gtk.css
index 99d35413e9..fb69a96494 100644
--- a/gtk/theme/HighContrast/gtk.css
+++ b/gtk/theme/HighContrast/gtk.css
@@ -2519,17 +2519,38 @@ stacksidebar row {
 /*********
  * Paned *
  *********/
-paned {
-  margin: 0 8px 8px 0; }
-  paned:dir(rtl) {
-    margin-right: 0;
-    margin-left: 8px; }
-  paned separator, paned placessidebar .view separator, placessidebar .view paned separator,
-  paned placessidebar .view separator:backdrop,
-  placessidebar .view paned separator:backdrop {
-    background-image: linear-gradient(to bottom, gray); }
-    paned separator:backdrop {
-      background-image: linear-gradient(to bottom, #8d8d8d); }
+paned separator, paned placessidebar .view separator, placessidebar .view paned separator,
+paned placessidebar .view separator:backdrop,
+placessidebar .view paned separator:backdrop {
+  min-width: 1px;
+  min-height: 1px;
+  background-image: linear-gradient(to bottom, gray); }
+  paned separator:backdrop {
+    background-image: linear-gradient(to bottom, #8d8d8d); }
+paned:dir(ltr).horizontal separator {
+  margin: 0 -8px 0 0;
+  padding: 0 8px 0 0; }
+paned:dir(rtl).horizontal separator {
+  margin: 0 0 0 -8px;
+  padding: 0 0 0 8px; }
+paned.vertical separator,
+paned.vertical placessidebar .view separator:backdrop,
+placessidebar .view paned.vertical separator:backdrop {
+  margin: 0 0 -8px 0;
+  padding: 0 0 8px 0; }
+paned separator:selected,
+paned placessidebar .view separator:selected:backdrop,
+placessidebar .view paned separator:selected:backdrop {
+  background-color: #000; }
+paned separator.wide,
+paned placessidebar .view separator.wide:backdrop,
+placessidebar .view paned separator.wide:backdrop {
+  min-width: 5px;
+  min-height: 5px;
+  background-color: transparent;
+  border-style: none solid;
+  border-color: gray;
+  border-width: 1px; }
 
 paned.wide {
   -GtkPaned-handle-size: 5;