Use --dimmed-opacity variable for navigation component opacities

Author: robertpiosik

packages/ui/src/components/editor/settings/NavigationItemGroup/NavigationItemGroup.module.scss

@@ -16,7 +16,7 @@
   height: 26px;
   padding-left: 20px;
   position: relative;
-  opacity: 0.6;
+  opacity: var(--dimmed-opacity);
 
   &:hover {
     background-color: var(--cwc-bg-tertiary);

packages/ui/src/components/editor/settings/NavigationItemSection/NavigationItemSection.module.scss

@@ -8,9 +8,10 @@
   color: var(--vscode-textLink-foreground);
   height: 32px;
   transition: background-color 0.1s;
+  opacity: var(--dimmed-opacity);
 
   &--active {
-    font-weight: 600;
+    opacity: 1;
   }
 }