diff --git a/src/app/globals.css b/src/app/globals.css
index 0cc9622..da61632 100644
--- a/src/app/globals.css
+++ b/src/app/globals.css
@@ -1001,28 +1001,14 @@
   }
 }
 
-/* Native fallback for containers that cannot use OverlayScrollbars (e.g. virtua) */
-.scrollbar-thin {
+/* Unified scrollbar style for scrollable containers.
+   Thin overlay scrollbar — no gutter reserved, no layout shift. */
+.scrollbar-thin,
+.scrollbar-thin-edge {
   scrollbar-width: thin;
   scrollbar-color: var(--border) transparent;
 }
 
-/* OverlayScrollbars custom theme */
-.os-theme-codeg {
-  --os-size: 6px;
-  --os-handle-bg: var(--border);
-  --os-handle-bg-hover: var(--muted-foreground);
-  --os-handle-bg-active: var(--muted-foreground);
-  --os-handle-border-radius: 999px;
-  --os-handle-perpendicular-size: 100%;
-  --os-handle-perpendicular-size-hover: 100%;
-  --os-handle-perpendicular-size-active: 100%;
-}
-
-.os-theme-codeg:hover {
-  --os-size: 8px;
-}
-
 /* Streamdown code blocks: dark mode via shiki dual-theme CSS variables */
 .dark [data-streamdown="code-block-body"] {
   background-color: var(--shiki-dark-bg, var(--sdm-bg, transparent)) !important;
diff --git a/src/components/overlay-scrollbars-init.tsx b/src/components/overlay-scrollbars-init.tsx
index 41762ff..c4f6c9e 100644
--- a/src/components/overlay-scrollbars-init.tsx
+++ b/src/components/overlay-scrollbars-init.tsx
@@ -22,4 +22,4 @@ export function OverlayScrollbarsInit() {
   }, [init])
 
   return null
-}
+}
\ No newline at end of file