refactor(ui): adjust global navigation bar style (#13419)

### What problem does this PR solve?

Renovate global navigation bar, align styles to the design.
(May causes minor layout issues in sub-pages, will check and fix soon)

### Type of change

- [x] Refactoring

web/tailwind.css

@@ -286,6 +286,14 @@
   }
 }
 
+@layer base {
+  * {
+    /* Make this default */
+    scrollbar-width: thin;
+    scrollbar-color: var(--border-default) var(--bg-card);
+  }
+}
+
 @layer utilities {
   .scrollbar-auto {
     /* hide scrollbar */