diff --git a/src/public/stylesheets/theme-next.css b/src/public/stylesheets/theme-next.css
index 20eec54e4..aa3621d50 100644
--- a/src/public/stylesheets/theme-next.css
+++ b/src/public/stylesheets/theme-next.css
@@ -46,6 +46,8 @@
     --tab-height: 36px;
     --tab-first-item-horiz-offset: 1px;
     --new-tab-button-size: 24px;
+
+    --center-pane-border-radius: 10px;
 }
 
 /*
@@ -99,6 +101,7 @@
    --modal-background-color: white;
    --modal-backdrop-color: black;
 
+   --left-pane-collapsed-border-color: #0000000d;
    --left-pane-background-color: #f2f2f2;
    --left-pane-text-color: #383838;
    --left-pane-item-hover-background: #eaeaea;
@@ -208,6 +211,7 @@
         --modal-background-color: #333;
         --modal-backdrop-color: #444;
     
+        --left-pane-collapsed-border-color: #0000000d;
         --left-pane-background-color: #1f1f1f;
         --left-pane-text-color: #AAAAAA;
         --left-pane-item-hover-background: #eaeaea;
@@ -292,6 +296,15 @@
     background-color: var(--root-background);
 }
 
+/* Matches when the left pane is collapsed */
+:has(#left-pane.hidden-int) {
+    --center-pane-border-radius: 0;
+    --tab-first-item-horiz-offset: 5px;
+}
+
+:has(#left-pane.hidden-int) #launcher-pane.vertical {
+    border-right: 2px solid var(--left-pane-collapsed-border-color);
+}
 
 /*
  *  Launcher pane
@@ -581,7 +594,7 @@
  */
 
  #center-pane {
-    border-radius: 10px 0 0 0;
+    border-radius: var(--center-pane-border-radius) 0 0 0;
     padding-top: 30px;
     background: var(--main-background-color);
  }