diff --git a/ai-pdf-chatbot/app/chat/[chatId]/page.tsx b/ai-pdf-chatbot/app/chat/[chatId]/page.tsx
index c845527..b9b644d 100644
--- a/ai-pdf-chatbot/app/chat/[chatId]/page.tsx
+++ b/ai-pdf-chatbot/app/chat/[chatId]/page.tsx
@@ -76,7 +76,7 @@ export default function ChatDetailPage({ params }: { params: Promise<{ chatId: s
           onShareTokenChange={setShareToken}
         />
       </div>
-      <div className="flex-1 overflow-y-auto px-4 py-6">
+      <div className="min-h-0 flex-1 overflow-y-auto px-4 py-6">
         <div className="mx-auto flex max-w-2xl flex-col gap-4">
           {messages
             .filter((m) => m.role !== 'system')
diff --git a/ai-pdf-chatbot/app/chat/page.tsx b/ai-pdf-chatbot/app/chat/page.tsx
index 0d6b279..998187c 100644
--- a/ai-pdf-chatbot/app/chat/page.tsx
+++ b/ai-pdf-chatbot/app/chat/page.tsx
@@ -88,7 +88,7 @@ function ChatHomePageInner() {
 
   return (
     <>
-      <div className="flex-1 overflow-y-auto px-4 py-6">
+      <div className="min-h-0 flex-1 overflow-y-auto px-4 py-6">
         {pendingInput ? (
           <div className="mx-auto flex max-w-2xl flex-col gap-4">
             <ChatMessage role="user" content={pendingInput} />
diff --git a/ai-pdf-chatbot/components/chat-input.tsx b/ai-pdf-chatbot/components/chat-input.tsx
index 1308837..065bed5 100644
--- a/ai-pdf-chatbot/components/chat-input.tsx
+++ b/ai-pdf-chatbot/components/chat-input.tsx
@@ -23,7 +23,7 @@ export function ChatInput({
   }
 
   return (
-    <form onSubmit={handle} className="flex items-end gap-2 border-t border-border bg-card/40 p-4">
+    <form onSubmit={handle} className="flex shrink-0 items-end gap-2 border-t border-border bg-card/40 p-4">
       <Textarea
         value={value}
         onChange={(e) => setValue(e.target.value)}
diff --git a/ai-pdf-chatbot/components/chat-shell.tsx b/ai-pdf-chatbot/components/chat-shell.tsx
index b8c11eb..1f6aee4 100644
--- a/ai-pdf-chatbot/components/chat-shell.tsx
+++ b/ai-pdf-chatbot/components/chat-shell.tsx
@@ -265,8 +265,8 @@ export function ChatShell({ children }: { children: React.ReactNode }) {
           <span className="truncate text-sm font-medium">AI PDF Chatbot</span>
         </header>
 
-        <main className="flex min-w-0 flex-1">
-          <section className="flex min-w-0 flex-1 flex-col">{children}</section>
+        <main className="flex min-h-0 min-w-0 flex-1">
+          <section className="flex min-h-0 min-w-0 flex-1 flex-col">{children}</section>
           <CitationRail citations={railCitations} />
         </main>
       </div>