diff --git a/apps/x/apps/renderer/src/App.tsx b/apps/x/apps/renderer/src/App.tsx
index 8a5548da..c41833de 100644
--- a/apps/x/apps/renderer/src/App.tsx
+++ b/apps/x/apps/renderer/src/App.tsx
@@ -80,11 +80,6 @@ type ConversationItem = ChatMessage | ToolCall | ReasoningBlock;
 
 type ToolState = 'input-streaming' | 'input-available' | 'output-available' | 'output-error';
 
-const estimateTokens = (text: string) => {
-  if (!text) return 0
-  return Math.ceil(text.trim().length / 4)
-}
-
 const isChatMessage = (item: ConversationItem): item is ChatMessage => 'role' in item
 const isToolCall = (item: ConversationItem): item is ToolCall => 'name' in item
 const isReasoningBlock = (item: ConversationItem): item is ReasoningBlock =>
@@ -274,7 +269,7 @@ function ChatInputInner({
         placeholder="Type your message..."
         disabled={isProcessing}
         onKeyDown={handleKeyDown}
-        className="min-h-[1.5rem] py-0 border-0 shadow-none focus-visible:ring-0 rounded-none"
+        className="min-h-6 py-0 border-0 shadow-none focus-visible:ring-0 rounded-none"
       />
       <Button
         size="icon"
@@ -348,7 +343,7 @@ function App() {
   const [conversation, setConversation] = useState<ConversationItem[]>([])
   const [currentAssistantMessage, setCurrentAssistantMessage] = useState<string>('')
   const [currentReasoning, setCurrentReasoning] = useState<string>('')
-  const [modelUsage, setModelUsage] = useState<LanguageModelUsage | null>(null)
+  const [, setModelUsage] = useState<LanguageModelUsage | null>(null)
   const [runId, setRunId] = useState<string | null>(null)
   const [isProcessing, setIsProcessing] = useState(false)
   const [agentId] = useState<string>('copilot')
@@ -718,6 +713,11 @@ function App() {
     handlePromptSubmit({ text, files: [] })
   }
 
+  const handleOpenFullScreenChat = useCallback(() => {
+    setSelectedPath(null)
+    setIsGraphOpen(false)
+  }, [])
+
   const toggleExpand = (path: string, kind: 'file' | 'dir') => {
     if (kind === 'file') {
       setSelectedPath(path)
@@ -1057,38 +1057,6 @@ function App() {
     return null
   }
 
-  const chatMessages = conversation.filter(isChatMessage)
-  const reasoningBlocks = conversation.filter(isReasoningBlock)
-  const estimatedInputTokens = chatMessages
-    .filter((item) => item.role === 'user')
-    .reduce((total, item) => total + estimateTokens(item.content), 0)
-  const estimatedOutputTokens = chatMessages
-    .filter((item) => item.role === 'assistant')
-    .reduce((total, item) => total + estimateTokens(item.content), 0)
-    + estimateTokens(currentAssistantMessage)
-  const estimatedReasoningTokens = reasoningBlocks
-    .reduce((total, item) => total + estimateTokens(item.content), 0)
-    + estimateTokens(currentReasoning)
-  const estimatedTotalTokens = estimatedInputTokens + estimatedOutputTokens + estimatedReasoningTokens
-  const maxTokens = 128_000
-  const estimatedUsage = {
-    inputTokens: estimatedInputTokens,
-    outputTokens: estimatedOutputTokens,
-    totalTokens: estimatedTotalTokens,
-    cachedInputTokens: 0,
-    reasoningTokens: estimatedReasoningTokens,
-  } as LanguageModelUsage
-  const effectiveUsage = modelUsage ?? estimatedUsage
-  const effectiveTotalTokens = effectiveUsage.totalTokens
-    ?? (effectiveUsage.inputTokens ?? 0)
-      + (effectiveUsage.outputTokens ?? 0)
-      + (effectiveUsage.reasoningTokens ?? 0)
-  const usedTokens = Math.min(effectiveTotalTokens, maxTokens)
-  const contextUsage = {
-    ...effectiveUsage,
-    totalTokens: effectiveTotalTokens,
-  } as LanguageModelUsage
-
   const hasConversation = conversation.length > 0 || currentAssistantMessage || currentReasoning
   const conversationContentClassName = hasConversation
     ? "mx-auto w-full max-w-4xl pb-28"
@@ -1262,6 +1230,7 @@ function App() {
                 defaultWidth={400}
                 isOpen={isChatSidebarOpen}
                 onNewChat={handleNewChat}
+                onOpenFullScreen={handleOpenFullScreenChat}
                 conversation={conversation}
                 currentAssistantMessage={currentAssistantMessage}
                 currentReasoning={currentReasoning}
diff --git a/apps/x/apps/renderer/src/components/chat-sidebar.tsx b/apps/x/apps/renderer/src/components/chat-sidebar.tsx
index c11fbfe4..01a30a08 100644
--- a/apps/x/apps/renderer/src/components/chat-sidebar.tsx
+++ b/apps/x/apps/renderer/src/components/chat-sidebar.tsx
@@ -1,5 +1,5 @@
 import { useCallback, useEffect, useMemo, useRef, useState } from 'react'
-import { ArrowUp, Plus } from 'lucide-react'
+import { ArrowUp, Expand, Plus } from 'lucide-react'
 import type { ToolUIPart } from 'ai'
 import { Button } from '@/components/ui/button'
 import { cn } from '@/lib/utils'
@@ -105,6 +105,7 @@ interface ChatSidebarProps {
   defaultWidth?: number
   isOpen?: boolean
   onNewChat: () => void
+  onOpenFullScreen?: () => void
   conversation: ConversationItem[]
   currentAssistantMessage: string
   currentReasoning: string
@@ -122,6 +123,7 @@ export function ChatSidebar({
   defaultWidth = DEFAULT_WIDTH,
   isOpen = true,
   onNewChat,
+  onOpenFullScreen,
   conversation,
   currentAssistantMessage,
   currentReasoning,
@@ -136,6 +138,17 @@ export function ChatSidebar({
 }: ChatSidebarProps) {
   const [width, setWidth] = useState(defaultWidth)
   const [isResizing, setIsResizing] = useState(false)
+  const [showContent, setShowContent] = useState(isOpen)
+
+  // Delay showing content when opening, hide immediately when closing
+  useEffect(() => {
+    if (isOpen) {
+      const timer = setTimeout(() => setShowContent(true), 150)
+      return () => clearTimeout(timer)
+    } else {
+      setShowContent(false)
+    }
+  }, [isOpen])
   const startXRef = useRef(0)
   const startWidthRef = useRef(0)
   const textareaRef = useRef<HTMLTextAreaElement>(null)
@@ -414,17 +427,30 @@ export function ChatSidebar({
         )}
       />
 
-      {/* Header - minimal, just new chat button */}
-      <header className="flex h-12 shrink-0 items-center justify-end px-2">
-        <Tooltip>
-          <TooltipTrigger asChild>
-            <Button variant="ghost" size="icon" onClick={onNewChat} className="h-8 w-8 text-muted-foreground hover:text-foreground">
-              <Plus className="h-4 w-4" />
-            </Button>
-          </TooltipTrigger>
-          <TooltipContent side="bottom">New chat</TooltipContent>
-        </Tooltip>
-      </header>
+      {/* Content - delayed on open, hidden immediately on close to avoid layout issues during animation */}
+      {showContent && (
+        <>
+          {/* Header - minimal, expand and new chat buttons */}
+          <header className="flex h-12 shrink-0 items-center justify-end gap-1 px-2">
+            {onOpenFullScreen && (
+              <Tooltip>
+                <TooltipTrigger asChild>
+                  <Button variant="ghost" size="icon" onClick={onOpenFullScreen} className="h-8 w-8 text-muted-foreground hover:text-foreground">
+                    <Expand className="h-4 w-4" />
+                  </Button>
+                </TooltipTrigger>
+                <TooltipContent side="bottom">Full screen chat</TooltipContent>
+              </Tooltip>
+            )}
+            <Tooltip>
+              <TooltipTrigger asChild>
+                <Button variant="ghost" size="icon" onClick={onNewChat} className="h-8 w-8 text-muted-foreground hover:text-foreground">
+                  <Plus className="h-4 w-4" />
+                </Button>
+              </TooltipTrigger>
+              <TooltipContent side="bottom">New chat</TooltipContent>
+            </Tooltip>
+          </header>
 
       {/* Conversation area */}
       <div className="flex min-h-0 flex-1 flex-col relative">
@@ -536,6 +562,8 @@ export function ChatSidebar({
           )}
         </div>
       </div>
+        </>
+      )}
     </div>
   )
 }