diff --git a/tests/prototype-sync-regression.spec.ts b/tests/prototype-sync-regression.spec.ts
index 40060fd..7817571 100644
--- a/tests/prototype-sync-regression.spec.ts
+++ b/tests/prototype-sync-regression.spec.ts
@@ -359,6 +359,83 @@ test('公开回答只播放服务端音频，缺失时保留文字且不调用
   await expect.poll(() => page.evaluate(() => (window as unknown as { __speechSynthesisUtteranceCalls: number }).__speechSynthesisUtteranceCalls)).toBe(0)
 })
 
+test('悬浮数字人向宿主上报拖动并应用宿主主题', async ({ page }) => {
+  await installMocks(page)
+  await page.route('**/widget-protocol-host', (route) => route.fulfill({
+    status: 200,
+    contentType: 'text/html; charset=utf-8',
+    body: `<!doctype html><html><body>
+      <iframe id="widget" src="/embed/published-agent" title="数字教员" allow="autoplay; microphone"
+        style="position:fixed;right:16px;bottom:16px;width:208px;height:92px;border:0"></iframe>
+      <script>
+        var frame = document.getElementById('widget');
+        var drag = null;
+        addEventListener('message', function (event) {
+          var data = event.data || {};
+          if (event.source !== frame.contentWindow || event.origin !== location.origin || data.source !== 'virtual-instructor-widget') return;
+          if (data.type === 'ready') frame.contentWindow.postMessage({
+            source: 'virtual-instructor-widget-host', type: 'theme',
+            theme: { scheme:'light', accent:'#197fc8', accentHover:'#1269aa', surface:'#ffffff', surfaceMuted:'#f1f6f9', text:'#17354d', textMuted:'#526d81', border:'#d2dfe8' }
+          }, location.origin);
+          if (data.type === 'resize') {
+            frame.style.width = data.width + 'px';
+            frame.style.height = data.height + 'px';
+          }
+          if (data.type === 'drag-start') {
+            var rect = frame.getBoundingClientRect();
+            drag = { left: rect.left, top: rect.top };
+          }
+          if (data.type === 'drag-move' && drag) {
+            drag.left += data.deltaX;
+            drag.top += data.deltaY;
+            frame.style.left = drag.left + 'px';
+            frame.style.top = drag.top + 'px';
+            frame.style.right = 'auto';
+            frame.style.bottom = 'auto';
+          }
+          if (data.type === 'drag-end') {
+            document.body.dataset.dragEnded = 'true';
+            drag = null;
+          }
+        });
+      <\/script>
+    </body></html>`,
+  }))
+
+  await page.goto('/widget-protocol-host')
+  const widgetFrame = page.locator('#widget')
+  const launcher = page.frameLocator('#widget').locator('.embed-launcher')
+  await expect(launcher).toBeVisible()
+  const before = await widgetFrame.boundingBox()
+  const launcherBox = await launcher.boundingBox()
+  expect(before).not.toBeNull()
+  expect(launcherBox).not.toBeNull()
+  await page.mouse.move(launcherBox!.x + launcherBox!.width / 2, launcherBox!.y + launcherBox!.height / 2)
+  await page.mouse.down()
+  await page.mouse.move(launcherBox!.x - 150, launcherBox!.y - 90, { steps: 8 })
+  await page.mouse.up()
+  await expect(page.locator('body')).toHaveAttribute('data-drag-ended', 'true')
+  await expect.poll(async () => (await widgetFrame.boundingBox())?.x).toBeLessThan(before!.x - 100)
+  await expect(page.frameLocator('#widget').locator('.embed-widget')).not.toHaveClass(/is-expanded/)
+
+  await launcher.click()
+  const panel = page.frameLocator('#widget').locator('.embed-panel')
+  await expect(panel).toBeVisible()
+  const panelHead = page.frameLocator('#widget').locator('.embed-panel-head')
+  await expect(panelHead).toHaveCSS('background-color', 'rgb(25, 127, 200)')
+  const beforePanelDrag = await widgetFrame.boundingBox()
+  const panelHeadBox = await panelHead.boundingBox()
+  expect(beforePanelDrag).not.toBeNull()
+  expect(panelHeadBox).not.toBeNull()
+  await page.locator('body').evaluate((body) => delete body.dataset.dragEnded)
+  await page.mouse.move(panelHeadBox!.x + panelHeadBox!.width / 2, panelHeadBox!.y + panelHeadBox!.height / 2)
+  await page.mouse.down()
+  await page.mouse.move(panelHeadBox!.x - 80, panelHeadBox!.y - 50, { steps: 6 })
+  await page.mouse.up()
+  await expect(page.locator('body')).toHaveAttribute('data-drag-ended', 'true')
+  await expect.poll(async () => (await widgetFrame.boundingBox())?.x).toBeLessThan(beforePanelDrag!.x - 50)
+})
+
 test('标签达到上限时静默淘汰最久未访问项', async ({ page }) => {
   await installMocks(page)
   await page.addInitScript(() => {
