style(chat): update styling for main content and chat input

- Add border and inset shadow to main content area
- Remove border from chat input on large screens and adjust shadow

src/App.tsx

@@ -55,7 +55,7 @@ const AppLayout: FC = () => {
       <div className="drawer-content flex flex-col w-full h-screen px-1 md:px-2 bg-base-300">
         <Header />
         <main
-          className="grow flex flex-col overflow-auto bg-base-100 rounded-xl"
+          className="grow flex flex-col overflow-auto bg-base-100 rounded-xl border-1 border-base-content/20 border-input inset-shadow-sm"
           id="main-scroll"
         >
           <Outlet />

src/pages/Chat/components/ChatInput.tsx

@@ -102,7 +102,7 @@ export const ChatInput = memo(
           disabled={isPending}
         >
           <div
-            className="bg-base-200 flex flex-col lg:border-1 lg:border-base-content/30 outline-0 focus-within:outline-1 rounded-lg shadow-sm md:shadow-md p-2"
+            className="bg-base-200 flex flex-col outline-0 focus-within:outline-1 rounded-lg shadow-sm xl:shadow-md p-2"
             tabIndex={0}
           >
             <AutoSizingTextArea