diff --git a/gtk/theme/Adwaita/_drawing.scss b/gtk/theme/Adwaita/_drawing.scss
index 9f8e832d6a..0fe49af4d9 100644
--- a/gtk/theme/Adwaita/_drawing.scss
+++ b/gtk/theme/Adwaita/_drawing.scss
@@ -594,7 +594,7 @@
 
   $_gradient_dir: left;
   $_dash_bg_size: 10px 1px;
-  $_base_bg_size: 10px 3px;
+  $_base_bg_size: 10px 1px;
   $_gradient_repeat: repeat-x;
   $_bg_pos: center $p;
 
@@ -603,19 +603,17 @@
   @if ($p == left) or ($p == right) {
     $_gradient_dir: top;
     $_dash_bg_size: 1px 10px;
-    $_base_bg_size: 3px 10px;
+    $_base_bg_size: 1px 10px;
     $_gradient_repeat: repeat-y;
     $_bg_pos: $p center;
   }
 
   background-image: linear-gradient(to $_gradient_dir, // this is the dash
-                                    transparentize($_undershoot_color, 1) 10%,
-                                    $_undershoot_color 10%,
-                                    $_undershoot_color 60%,
-                                    transparentize($_undershoot_color, 1) 60%),
+                                    $_undershoot_color 50%,
+                                    transparentize($_undershoot_color, 1) 50%),
                     linear-gradient(to $_gradient_dir, // this is the dash base
-                                    $_undershoot_base 70%,
-                                    transparentize($_undershoot_base, 1) 70%);
+                                    $_undershoot_base 50%,
+                                    transparentize($_undershoot_base, 1) 50%);
 
   border-#{$p}: 1px solid transparent;
   padding-#{$p}: 1px;
diff --git a/gtk/theme/Adwaita/gtk-contained-dark.css b/gtk/theme/Adwaita/gtk-contained-dark.css
index ffe4f7daac..b66656c146 100644
--- a/gtk/theme/Adwaita/gtk-contained-dark.css
+++ b/gtk/theme/Adwaita/gtk-contained-dark.css
@@ -4415,37 +4415,37 @@ GtkVolumeButton.button, .header-bar GtkVolumeButton.button.titlebutton,
 
 .undershoot.top {
   background-color: transparent;
-  background-image: linear-gradient(to left, rgba(238, 238, 236, 0) 10%, rgba(238, 238, 236, 0.4) 10%, rgba(238, 238, 236, 0.4) 60%, rgba(238, 238, 236, 0) 60%), linear-gradient(to left, rgba(41, 41, 41, 0.5) 70%, rgba(41, 41, 41, 0) 70%);
+  background-image: linear-gradient(to left, rgba(238, 238, 236, 0.4) 50%, rgba(238, 238, 236, 0) 50%), linear-gradient(to left, rgba(41, 41, 41, 0.5) 50%, rgba(41, 41, 41, 0) 50%);
   border-top: 1px solid transparent;
   padding-top: 1px;
-  background-size: 10px 1px, 10px 3px;
+  background-size: 10px 1px, 10px 1px;
   background-repeat: repeat-x;
   background-origin: content-box, padding-box;
   background-position: center top; }
 .undershoot.bottom {
   background-color: transparent;
-  background-image: linear-gradient(to left, rgba(238, 238, 236, 0) 10%, rgba(238, 238, 236, 0.4) 10%, rgba(238, 238, 236, 0.4) 60%, rgba(238, 238, 236, 0) 60%), linear-gradient(to left, rgba(41, 41, 41, 0.5) 70%, rgba(41, 41, 41, 0) 70%);
+  background-image: linear-gradient(to left, rgba(238, 238, 236, 0.4) 50%, rgba(238, 238, 236, 0) 50%), linear-gradient(to left, rgba(41, 41, 41, 0.5) 50%, rgba(41, 41, 41, 0) 50%);
   border-bottom: 1px solid transparent;
   padding-bottom: 1px;
-  background-size: 10px 1px, 10px 3px;
+  background-size: 10px 1px, 10px 1px;
   background-repeat: repeat-x;
   background-origin: content-box, padding-box;
   background-position: center bottom; }
 .undershoot.left {
   background-color: transparent;
-  background-image: linear-gradient(to top, rgba(238, 238, 236, 0) 10%, rgba(238, 238, 236, 0.4) 10%, rgba(238, 238, 236, 0.4) 60%, rgba(238, 238, 236, 0) 60%), linear-gradient(to top, rgba(41, 41, 41, 0.5) 70%, rgba(41, 41, 41, 0) 70%);
+  background-image: linear-gradient(to top, rgba(238, 238, 236, 0.4) 50%, rgba(238, 238, 236, 0) 50%), linear-gradient(to top, rgba(41, 41, 41, 0.5) 50%, rgba(41, 41, 41, 0) 50%);
   border-left: 1px solid transparent;
   padding-left: 1px;
-  background-size: 1px 10px, 3px 10px;
+  background-size: 1px 10px, 1px 10px;
   background-repeat: repeat-y;
   background-origin: content-box, padding-box;
   background-position: left center; }
 .undershoot.right {
   background-color: transparent;
-  background-image: linear-gradient(to top, rgba(238, 238, 236, 0) 10%, rgba(238, 238, 236, 0.4) 10%, rgba(238, 238, 236, 0.4) 60%, rgba(238, 238, 236, 0) 60%), linear-gradient(to top, rgba(41, 41, 41, 0.5) 70%, rgba(41, 41, 41, 0) 70%);
+  background-image: linear-gradient(to top, rgba(238, 238, 236, 0.4) 50%, rgba(238, 238, 236, 0) 50%), linear-gradient(to top, rgba(41, 41, 41, 0.5) 50%, rgba(41, 41, 41, 0) 50%);
   border-right: 1px solid transparent;
   padding-right: 1px;
-  background-size: 1px 10px, 3px 10px;
+  background-size: 1px 10px, 1px 10px;
   background-repeat: repeat-y;
   background-origin: content-box, padding-box;
   background-position: right center; }
diff --git a/gtk/theme/Adwaita/gtk-contained.css b/gtk/theme/Adwaita/gtk-contained.css
index 775a786feb..f6c279ac3b 100644
--- a/gtk/theme/Adwaita/gtk-contained.css
+++ b/gtk/theme/Adwaita/gtk-contained.css
@@ -4588,37 +4588,37 @@ GtkVolumeButton.button, .header-bar GtkVolumeButton.button.titlebutton,
 
 .undershoot.top {
   background-color: transparent;
-  background-image: linear-gradient(to left, rgba(46, 52, 54, 0) 10%, rgba(46, 52, 54, 0.4) 10%, rgba(46, 52, 54, 0.4) 60%, rgba(46, 52, 54, 0) 60%), linear-gradient(to left, rgba(255, 255, 255, 0.5) 70%, rgba(255, 255, 255, 0) 70%);
+  background-image: linear-gradient(to left, rgba(46, 52, 54, 0.4) 50%, rgba(46, 52, 54, 0) 50%), linear-gradient(to left, rgba(255, 255, 255, 0.5) 50%, rgba(255, 255, 255, 0) 50%);
   border-top: 1px solid transparent;
   padding-top: 1px;
-  background-size: 10px 1px, 10px 3px;
+  background-size: 10px 1px, 10px 1px;
   background-repeat: repeat-x;
   background-origin: content-box, padding-box;
   background-position: center top; }
 .undershoot.bottom {
   background-color: transparent;
-  background-image: linear-gradient(to left, rgba(46, 52, 54, 0) 10%, rgba(46, 52, 54, 0.4) 10%, rgba(46, 52, 54, 0.4) 60%, rgba(46, 52, 54, 0) 60%), linear-gradient(to left, rgba(255, 255, 255, 0.5) 70%, rgba(255, 255, 255, 0) 70%);
+  background-image: linear-gradient(to left, rgba(46, 52, 54, 0.4) 50%, rgba(46, 52, 54, 0) 50%), linear-gradient(to left, rgba(255, 255, 255, 0.5) 50%, rgba(255, 255, 255, 0) 50%);
   border-bottom: 1px solid transparent;
   padding-bottom: 1px;
-  background-size: 10px 1px, 10px 3px;
+  background-size: 10px 1px, 10px 1px;
   background-repeat: repeat-x;
   background-origin: content-box, padding-box;
   background-position: center bottom; }
 .undershoot.left {
   background-color: transparent;
-  background-image: linear-gradient(to top, rgba(46, 52, 54, 0) 10%, rgba(46, 52, 54, 0.4) 10%, rgba(46, 52, 54, 0.4) 60%, rgba(46, 52, 54, 0) 60%), linear-gradient(to top, rgba(255, 255, 255, 0.5) 70%, rgba(255, 255, 255, 0) 70%);
+  background-image: linear-gradient(to top, rgba(46, 52, 54, 0.4) 50%, rgba(46, 52, 54, 0) 50%), linear-gradient(to top, rgba(255, 255, 255, 0.5) 50%, rgba(255, 255, 255, 0) 50%);
   border-left: 1px solid transparent;
   padding-left: 1px;
-  background-size: 1px 10px, 3px 10px;
+  background-size: 1px 10px, 1px 10px;
   background-repeat: repeat-y;
   background-origin: content-box, padding-box;
   background-position: left center; }
 .undershoot.right {
   background-color: transparent;
-  background-image: linear-gradient(to top, rgba(46, 52, 54, 0) 10%, rgba(46, 52, 54, 0.4) 10%, rgba(46, 52, 54, 0.4) 60%, rgba(46, 52, 54, 0) 60%), linear-gradient(to top, rgba(255, 255, 255, 0.5) 70%, rgba(255, 255, 255, 0) 70%);
+  background-image: linear-gradient(to top, rgba(46, 52, 54, 0.4) 50%, rgba(46, 52, 54, 0) 50%), linear-gradient(to top, rgba(255, 255, 255, 0.5) 50%, rgba(255, 255, 255, 0) 50%);
   border-right: 1px solid transparent;
   padding-right: 1px;
-  background-size: 1px 10px, 3px 10px;
+  background-size: 1px 10px, 1px 10px;
   background-repeat: repeat-y;
   background-origin: content-box, padding-box;
   background-position: right center; }