diff --git a/packages/frontend/core/src/blocksuite/ai/chat-panel/ai-title.ts b/packages/frontend/core/src/blocksuite/ai/chat-panel/ai-title.ts
index 2bf436526..9e8462b77 100644
--- a/packages/frontend/core/src/blocksuite/ai/chat-panel/ai-title.ts
+++ b/packages/frontend/core/src/blocksuite/ai/chat-panel/ai-title.ts
@@ -30,7 +30,7 @@ export class AIChatPanelTitle extends SignalWatcher(
     .ai-chat-panel-title {
       background: var(--affine-background-primary-color);
       position: relative;
-      padding: 8px var(--h-padding);
+      padding: 8px var(--h-padding, 16px);
       width: 100%;
       height: 36px;
       display: flex;
diff --git a/packages/frontend/core/src/blocksuite/ai/chat-panel/index.ts b/packages/frontend/core/src/blocksuite/ai/chat-panel/index.ts
index 2dbb14a98..a702917ad 100644
--- a/packages/frontend/core/src/blocksuite/ai/chat-panel/index.ts
+++ b/packages/frontend/core/src/blocksuite/ai/chat-panel/index.ts
@@ -40,6 +40,13 @@ export class ChatPanel extends SignalWatcher(
 
       .chat-panel-container {
         height: 100%;
+        display: flex;
+        flex-direction: column;
+      }
+
+      ai-chat-content {
+        height: 0;
+        flex-grow: 1;
       }
 
       .chat-loading-container {