diff --git a/src/__tests__/opencode_cell_actions.spec.ts b/src/__tests__/opencode_cell_actions.spec.ts
index 371c9db..7482a58 100644
--- a/src/__tests__/opencode_cell_actions.spec.ts
+++ b/src/__tests__/opencode_cell_actions.spec.ts
@@ -194,8 +194,11 @@ describe('OpenCodeCellActions', () => {
 
   it('renders a single AI button', () => {
     const cell = makeFakeCell('x = 1');
-    const actions = new OpenCodeCellActions(cell);
-    const btns = actions.node.querySelectorAll('button');
+    // Constructing the actions widget has the side effect of appending
+    // the floating AI button to cell.node; the widget reference itself
+    // is not needed in this test.
+    new OpenCodeCellActions(cell);
+    const btns = cell.node.querySelectorAll('button.opencode-cell-ai-btn');
     expect(btns.length).toBe(1);
     expect(btns[0].textContent).toContain('AI');
   });
@@ -210,8 +213,11 @@ describe('OpenCodeCellActions', () => {
       contentChanged: { connect: jest.fn(), disconnect: jest.fn() },
       stateChanged: { connect: jest.fn(), disconnect: jest.fn() }
     };
-    const actions = new OpenCodeCellActions(cell);
-    const btn = actions.node.querySelector('button') as HTMLButtonElement;
+    (cell as any).node = document.createElement('div');
+    new OpenCodeCellActions(cell);
+    const btn = cell.node.querySelector(
+      'button.opencode-cell-ai-btn'
+    ) as HTMLButtonElement;
     expect(btn.disabled).toBe(true);
   });
 
@@ -221,7 +227,7 @@ describe('OpenCodeCellActions', () => {
     Object.defineProperty(actions, 'parent', { value: cell, configurable: true });
     (actions as any).onAfterAttach({} as any);
 
-    const btn = actions.node.querySelector('button') as HTMLButtonElement;
+    const btn = cell.node.querySelector('button.opencode-cell-ai-btn') as HTMLButtonElement;
     btn.click();
 
     const prompt = cell.node.querySelector(
@@ -236,7 +242,7 @@ describe('OpenCodeCellActions', () => {
     Object.defineProperty(actions, 'parent', { value: cell, configurable: true });
     (actions as any).onAfterAttach({} as any);
 
-    const btn = actions.node.querySelector('button') as HTMLButtonElement;
+    const btn = cell.node.querySelector('button.opencode-cell-ai-btn') as HTMLButtonElement;
     btn.click();
     btn.click();
     expect(cell.node.querySelector('.opencode-inline-prompt')).toBeNull();
@@ -274,7 +280,7 @@ describe('OpenCodeCellActions', () => {
     Object.defineProperty(actions, 'parent', { value: cell, configurable: true });
     (actions as any).onAfterAttach({} as any);
 
-    const btn = actions.node.querySelector('button') as HTMLButtonElement;
+    const btn = cell.node.querySelector('button.opencode-cell-ai-btn') as HTMLButtonElement;
     btn.click();
 
     const prompt = cell.node.querySelector(
@@ -319,7 +325,7 @@ describe('OpenCodeCellActions', () => {
     Object.defineProperty(actions, 'parent', { value: cell, configurable: true });
     (actions as any).onAfterAttach({} as any);
 
-    const btn = actions.node.querySelector('button') as HTMLButtonElement;
+    const btn = cell.node.querySelector('button.opencode-cell-ai-btn') as HTMLButtonElement;
     btn.click();
 
     const modelSel = cell.node.querySelector(
@@ -348,7 +354,7 @@ describe('OpenCodeCellActions', () => {
     Object.defineProperty(actions, 'parent', { value: cell, configurable: true });
     (actions as any).onAfterAttach({} as any);
 
-    const btn = actions.node.querySelector('button') as HTMLButtonElement;
+    const btn = cell.node.querySelector('button.opencode-cell-ai-btn') as HTMLButtonElement;
     btn.click();
 
     const prompt = cell.node.querySelector(
@@ -384,7 +390,7 @@ describe('OpenCodeCellActions', () => {
     Object.defineProperty(actions, 'parent', { value: cell, configurable: true });
     (actions as any).onAfterAttach({} as any);
 
-    const btn = actions.node.querySelector('button') as HTMLButtonElement;
+    const btn = cell.node.querySelector('button.opencode-cell-ai-btn') as HTMLButtonElement;
     btn.click();
 
     expect(
@@ -403,7 +409,7 @@ describe('OpenCodeCellActions', () => {
     // has a target and the cell source check has a baseline).
     Object.defineProperty(actions, 'parent', { value: cell, configurable: true });
     (actions as any).onAfterAttach({} as any);
-    const btn = actions.node.querySelector('button') as HTMLButtonElement;
+    const btn = cell.node.querySelector('button.opencode-cell-ai-btn') as HTMLButtonElement;
     btn.click();
 
     // The history refresh on show is async; spy on _refreshHistory to
@@ -422,6 +428,34 @@ describe('OpenCodeCellActions', () => {
     // A history refresh was triggered (to pick up the new assistant msg).
     expect(refreshSpy).toHaveBeenCalledWith('foo.ipynb');
   });
+
+  it('clears the input textarea after a successful response', () => {
+    setOpenCodeProviders(null);
+    const cell = makeFakeCell('x = 1');
+    const actions = new OpenCodeCellActions(cell);
+    Object.defineProperty(actions, 'parent', { value: cell, configurable: true });
+    (actions as any).onAfterAttach({} as any);
+
+    // Open the prompt and type something into the textarea.
+    const aiBtn = cell.node.querySelector(
+      'button.opencode-cell-ai-btn'
+    ) as HTMLButtonElement;
+    aiBtn.click();
+    const prompt = (actions as any)._prompt;
+    expect(prompt).not.toBeNull();
+    const textarea = prompt._textarea as HTMLTextAreaElement;
+    textarea.value = 'make it faster';
+
+    // A successful response clears the input so the user can type a
+    // follow-up message.
+    (actions as any)._handleResponse({
+      ok: true,
+      markdown: 'ok',
+      sessionId: 'ses-1',
+      notebookPath: 'foo.ipynb'
+    });
+    expect(textarea.value).toBe('');
+  });
 });
 
 describe('OpenCodeInlinePrompt', () => {
diff --git a/src/components/opencode_cell_actions.ts b/src/components/opencode_cell_actions.ts
index d64bfaf..b70085c 100644
--- a/src/components/opencode_cell_actions.ts
+++ b/src/components/opencode_cell_actions.ts
@@ -50,11 +50,22 @@ export class OpenCodeCellActions extends Widget {
   private _context: CellContext | null = null;
   private _status: Status = 'idle';
   private _prompt: OpenCodeInlinePrompt | null = null;
+  // Floating "AI" entry button that lives at the cell's bottom-right
+  // corner (overlaid on the cell, absolutely positioned). The widget's
+  // own node stays inside the native cell toolbar (as a hidden lifecycle
+  // holder) and is NOT where the user-visible button renders.
+  private _floatingBtn: HTMLButtonElement | null = null;
 
   constructor(cell: CodeCell) {
     super();
     this._cell = cell;
     this.addClass('opencode-cell-actions');
+    // Hide the widget's own node inside the native cell toolbar — the
+    // actual UI is the floating button below.
+    this.node.style.display = 'none';
+    // Anchor the absolutely-positioned floating button to the cell.
+    this._cell.node.style.position = 'relative';
+    this._createFloatingButton();
     this._cell.model.contentChanged.connect(this._onModelChange, this);
     this._cell.model.stateChanged.connect(this._onModelChange, this);
     this._render();
@@ -68,9 +79,26 @@ export class OpenCodeCellActions extends Widget {
     this._cell.model.contentChanged.disconnect(this._onModelChange, this);
     this._cell.model.stateChanged.disconnect(this._onModelChange, this);
     this._hidePrompt();
+    if (this._floatingBtn && this._floatingBtn.parentNode) {
+      this._floatingBtn.parentNode.removeChild(this._floatingBtn);
+    }
+    this._floatingBtn = null;
     super.dispose();
   }
 
+  private _createFloatingButton(): void {
+    const btn = document.createElement('button');
+    btn.className = 'opencode-cell-ai-btn';
+    btn.type = 'button';
+    btn.textContent = 'AI';
+    btn.title = '让 AI 修改这个 cell 的代码';
+    btn.addEventListener('click', () => {
+      this._togglePrompt();
+    });
+    this._cell.node.appendChild(btn);
+    this._floatingBtn = btn;
+  }
+
   private _onModelChange(): void {
     this._context = extractCellContextFromCell(this._cell);
     if (this._prompt) {
@@ -81,22 +109,18 @@ export class OpenCodeCellActions extends Widget {
   }
 
   private _render(): void {
-    const node = this.node;
-    node.textContent = '';
-
+    // The widget's own node no longer hosts the button (it lives at the
+    // cell's bottom-right). Just update the floating button's label and
+    // disabled state.
+    const btn = this._floatingBtn;
+    if (!btn) {
+      return;
+    }
     const baseDisabled = !this._context || this._status === 'loading';
-
-    const btn = document.createElement('button');
-    btn.className = 'opencode-btn opencode-btn-ai';
-    btn.textContent = 'AI';
     btn.disabled = baseDisabled;
     btn.title = baseDisabled
       ? 'OpenCode: 等待 cell 上下文…'
       : '让 AI 修改这个 cell 的代码';
-    btn.addEventListener('click', () => {
-      this._togglePrompt();
-    });
-    node.appendChild(btn);
   }
 
   private _togglePrompt(): void {
@@ -204,6 +228,8 @@ export class OpenCodeCellActions extends Widget {
       if (notebookPath) {
         void this._refreshHistory(notebookPath);
       }
+      // Clear the input so the user can type a follow-up message.
+      this._prompt?.clearInput();
       Notification.info(
         `OpenCode 完成 (${resp.markdown.length} chars). Session: ${resp.sessionId.slice(0, 8)}…`
       );
diff --git a/src/components/opencode_inline_prompt.ts b/src/components/opencode_inline_prompt.ts
index 9d692c8..c987551 100644
--- a/src/components/opencode_inline_prompt.ts
+++ b/src/components/opencode_inline_prompt.ts
@@ -367,4 +367,12 @@ export class OpenCodeInlinePrompt extends Widget {
     cell.model.sharedModel.setSource(text);
     Notification.info('已替换单元格内容');
   }
+
+  /**
+   * Clear the user input textarea (called by the cell action after a
+   * successful response, so the user can type a follow-up message).
+   */
+  clearInput(): void {
+    this._textarea.value = '';
+  }
 }
diff --git a/style/base.css b/style/base.css
index 6c23365..a6347bc 100644
--- a/style/base.css
+++ b/style/base.css
@@ -4,29 +4,31 @@
     https://jupyterlab.readthedocs.io/en/stable/developer/css.html
 */
 
-/* Single AI action button inside the native Cell toolbar (active cell, top-right). */
-.opencode-cell-actions {
-  display: flex;
-  align-items: center;
-}
-
-.opencode-cell-actions .opencode-btn {
-  border: none;
-  background: transparent;
-  padding: 0 6px;
-  font-size: var(--jp-ui-font-size1);
-  line-height: 20px;
+/* AI entry button: rendered as a floating pill at the bottom-right
+   corner of the cell. The widget that owns it (opencode-cell-actions)
+   is registered in the native cell toolbar but its own node is
+   display:none — only this floating button is visible. */
+.opencode-cell-ai-btn {
+  position: absolute;
+  bottom: 4px;
+  right: 4px;
+  z-index: 10;
+  border: 1px solid var(--jp-border-color1, #999);
+  background: var(--jp-layout-color1, #fff);
+  color: var(--jp-ui-font-color1, #333);
+  padding: 1px 8px;
+  border-radius: 10px;
+  font-size: var(--jp-ui-font-size0, 11px);
+  line-height: 1.3;
   cursor: pointer;
-  white-space: nowrap;
 }
 
-.opencode-cell-actions .opencode-btn:hover:enabled {
-  background: var(--jp-layout-color2);
-  border-radius: 2px;
+.opencode-cell-ai-btn:hover {
+  background: var(--jp-layout-color2, #f0f0f0);
 }
 
-.opencode-cell-actions .opencode-btn:disabled {
-  opacity: 0.4;
+.opencode-cell-ai-btn:disabled {
+  opacity: 0.5;
   cursor: default;
 }