Apply some tweaks on Admin UI (#11011)

### What problem does this PR solve?

- Fix selected radio button text misaligned with radio button dot
- Fix `<ScrollArea>` scrollbar z-index issue
- Add backdrop blur effect on scrollbar thumbs
- Adjust some styles to match the design 


### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

web/src/components/ui/scroll-area.tsx

@@ -13,6 +13,7 @@ const ScrollBar = React.forwardRef<
     ref={ref}
     orientation={orientation}
     className={cn(
+      'z-[100]',
       'flex touch-none select-none transition-colors',
       orientation === 'vertical' &&
         'h-full w-2.5 border-l border-l-transparent p-[1px]',
@@ -22,7 +23,7 @@ const ScrollBar = React.forwardRef<
     )}
     {...props}
   >
-    <ScrollAreaPrimitive.ScrollAreaThumb className="relative flex-1 rounded-full bg-border" />
+    <ScrollAreaPrimitive.ScrollAreaThumb className="relative flex-1 rounded-full bg-border backdrop-blur-md" />
   </ScrollAreaPrimitive.ScrollAreaScrollbar>
 ));
 ScrollBar.displayName = ScrollAreaPrimitive.ScrollAreaScrollbar.displayName;