diff --git a/src/features/agent/components/agent-history-panel.tsx b/src/features/agent/components/agent-history-panel.tsx
index e414311..6792d6d 100644
--- a/src/features/agent/components/agent-history-panel.tsx
+++ b/src/features/agent/components/agent-history-panel.tsx
@@ -187,7 +187,7 @@ export function AgentHistoryPanel({
                         <motion.button
                           key="session-summary"
                           type="button"
-                          className="min-w-0 text-left"
+                          className="agent-history-session-trigger min-w-0 text-left"
                           disabled={itemLoading || deleting}
                           initial="initial"
                           animate="animate"
diff --git a/src/styles.css b/src/styles.css
index 9eb9182..e1aebdb 100644
--- a/src/styles.css
+++ b/src/styles.css
@@ -761,6 +761,10 @@ button:disabled {
   background-color: var(--agent-floating-reading-active);
 }
 
+button.agent-history-session-trigger:not(:disabled):active {
+  outline: none;
+}
+
 .agent-history-rename-input,
 .agent-history-rename-input:focus-visible {
   border-color: #cbd5e1;
diff --git a/tests/browser/agent-acrylic.e2e.ts b/tests/browser/agent-acrylic.e2e.ts
index ad16c69..1d23772 100644
--- a/tests/browser/agent-acrylic.e2e.ts
+++ b/tests/browser/agent-acrylic.e2e.ts
@@ -134,6 +134,23 @@ test("desktop Agent header expands into one attached acrylic history surface", a
     .poll(() => getSurfacePresentation(historyButton))
     .toEqual(historyButtonPresentationBefore);
 
+  const sessionTrigger = history.locator(".agent-history-session-trigger").first();
+  const sessionTriggerBox = await sessionTrigger.boundingBox();
+  const historyHeadingBox = await history.getByText("历史记录", { exact: true }).boundingBox();
+  expect(sessionTriggerBox).not.toBeNull();
+  expect(historyHeadingBox).not.toBeNull();
+  await page.mouse.move(
+    sessionTriggerBox!.x + sessionTriggerBox!.width / 2,
+    sessionTriggerBox!.y + sessionTriggerBox!.height / 2
+  );
+  await page.mouse.down();
+  await expect(sessionTrigger).toHaveCSS("outline-style", "none");
+  await page.mouse.move(
+    historyHeadingBox!.x + historyHeadingBox!.width / 2,
+    historyHeadingBox!.y + historyHeadingBox!.height / 2
+  );
+  await page.mouse.up();
+
   const headerBox = await agentHeader.boundingBox();
   const agentPanelBox = await agentPanel.boundingBox();
   const historyBox = await history.boundingBox();