🎨 style: Improve Styling (#3205)

* style: add scrollbar-gutter to prevent layout shift

* style: better styling for simple/advanced tab and remove border-r on smaller screens

* style: better description styling

* style: make sure single response Messages style is the same as pre-multi-stream response feature

client/src/components/Prompts/PromptsView.tsx

@@ -46,7 +46,7 @@ export default function PromptsView() {
         </GroupSidePanel>
         <div
           className={cn(
-            'w-full overflow-y-auto lg:w-3/4 xl:w-3/4',
+            'scrollbar-gutter-stable w-full overflow-y-auto lg:w-3/4 xl:w-3/4',
             isDetailView ? 'block' : 'hidden md:block',
           )}
         >