diff --git a/packages/frontend/core/src/blocksuite/ai/chat-panel/content/pure-text.ts b/packages/frontend/core/src/blocksuite/ai/chat-panel/content/pure-text.ts
index b71fc0e86..167f14adf 100644
--- a/packages/frontend/core/src/blocksuite/ai/chat-panel/content/pure-text.ts
+++ b/packages/frontend/core/src/blocksuite/ai/chat-panel/content/pure-text.ts
@@ -8,7 +8,7 @@ export class ChatContentPureText extends ShadowlessElement {
     .chat-content-pure-text {
       display: inline-block;
       text-align: left;
-      max-width: 800px;
+      max-width: 100%;
       max-height: 500px;
       overflow-y: auto;
       overflow-x: hidden;
diff --git a/packages/frontend/core/src/blocksuite/ai/chat-panel/message/user.ts b/packages/frontend/core/src/blocksuite/ai/chat-panel/message/user.ts
index 139c63d3f..0deea19f8 100644
--- a/packages/frontend/core/src/blocksuite/ai/chat-panel/message/user.ts
+++ b/packages/frontend/core/src/blocksuite/ai/chat-panel/message/user.ts
@@ -47,7 +47,11 @@ export class ChatMessageUser extends WithDisposable(ShadowlessElement) {
             .images=${item.attachments}
           ></chat-content-images>`
         : nothing}
-      <div class="text-content-wrapper" data-test-id="chat-content-user-text">
+      <div
+        class="text-content-wrapper"
+        data-test-id="chat-content-user-text"
+        style="max-width: 100%;"
+      >
         <chat-content-pure-text .text=${item.content}></chat-content-pure-text>
       </div>
     `;