diff --git a/scripts/src/dev-cloud-workbench-smoke-lib.mjs b/scripts/src/dev-cloud-workbench-smoke-lib.mjs
index 0ed04fb7..1127a7e7 100644
--- a/scripts/src/dev-cloud-workbench-smoke-lib.mjs
+++ b/scripts/src/dev-cloud-workbench-smoke-lib.mjs
@@ -942,6 +942,12 @@ export async function runDevCloudWorkbenchMobileSmoke() {
     });
     await page.goto(server.url, { waitUntil: "networkidle", timeout: 15000 });
     const closed = await inspectMobileWorkbench(page, { explorerOpen: false });
+    const workspaceScroll = await inspectWorkbenchScrollContract(page, { panelSelector: "#conversation-list" });
+    await page.click('[data-route="help"]');
+    await page.waitForFunction(() => document.querySelector("#help-content")?.dataset.helpState === "ready", null, { timeout: 8000 });
+    const help = await inspectHelpMarkdownRoute(page);
+    await page.click('[data-route="workspace"]');
+    await page.waitForFunction(() => document.querySelector('[data-view="workspace"]')?.hidden === false, null, { timeout: 8000 });
     await page.click("#explorer-toggle");
     const open = await inspectMobileWorkbench(page, { explorerOpen: true });
     await page.click('[data-side-tab-jump="wiring"]');
@@ -960,6 +966,25 @@ export async function runDevCloudWorkbenchMobileSmoke() {
           visibleText: closed.visibleText
         }
       },
+      {
+        id: "mobile-outer-scroll-lock",
+        status: workspaceScroll.outerScrollLocked && help.rootStillLocked && help.helpPanelScrolls ? "pass" : "blocked",
+        summary: "390x844 page locks outer scrolling while the internal Markdown help pane owns overflow scrolling.",
+        observations: {
+          workspace: workspaceScroll,
+          help: {
+            rootStillLocked: help.rootStillLocked,
+            helpPanelScrolls: help.helpPanelScrolls,
+            helpScroll: help.helpScroll
+          }
+        }
+      },
+      {
+        id: "mobile-help-markdown-route",
+        status: help.nonDefaultMarkdownHelp && help.termsPresent ? "pass" : "blocked",
+        summary: "Help opens as a non-default internal route rendered from help.md by the vendored Markdown renderer.",
+        observations: help
+      },
       {
         id: "mobile-default-hit-test",
         status: closed.primaryControlsReachable ? "pass" : "blocked",
@@ -1197,6 +1222,130 @@ async function inspectMobileWorkbench(page, { explorerOpen }) {
   }, { explorerOpen });
 }
 
+async function inspectWorkbenchScrollContract(page, { panelSelector }) {
+  return page.evaluate(async ({ panelSelector }) => {
+    function metrics(selector) {
+      const element = selector === "html" ? document.documentElement : selector === "body" ? document.body : document.querySelector(selector);
+      if (!element) return null;
+      const style = getComputedStyle(element);
+      return {
+        selector,
+        overflow: style.overflow,
+        overflowY: style.overflowY,
+        height: element.getBoundingClientRect().height,
+        clientHeight: element.clientHeight,
+        scrollHeight: element.scrollHeight,
+        scrollTop: element.scrollTop
+      };
+    }
+
+    window.scrollTo(0, 240);
+    document.documentElement.scrollTop = 240;
+    document.body.scrollTop = 240;
+    await new Promise((resolve) => requestAnimationFrame(resolve));
+    const rootAfterScrollAttempt = {
+      windowScrollY: window.scrollY,
+      htmlScrollTop: document.documentElement.scrollTop,
+      bodyScrollTop: document.body.scrollTop
+    };
+
+    const panel = document.querySelector(panelSelector);
+    const beforePanelScroll = panel?.scrollTop ?? null;
+    if (panel) {
+      panel.scrollTop = 0;
+      await new Promise((resolve) => requestAnimationFrame(resolve));
+      panel.scrollTop = panel.scrollHeight;
+      await new Promise((resolve) => requestAnimationFrame(resolve));
+    }
+    const afterPanelScroll = panel?.scrollTop ?? null;
+    const html = metrics("html");
+    const body = metrics("body");
+    const shell = metrics("[data-app-shell]");
+    const panelMetrics = metrics(panelSelector);
+    const rootScrollLocked =
+      html?.overflow === "hidden" &&
+      body?.overflow === "hidden" &&
+      Math.abs((shell?.height ?? 0) - window.innerHeight) <= 2 &&
+      document.documentElement.scrollHeight <= document.documentElement.clientHeight + 2 &&
+      document.body.scrollHeight <= document.body.clientHeight + 2 &&
+      window.scrollY === 0 &&
+      document.documentElement.scrollTop === 0 &&
+      document.body.scrollTop === 0;
+    return {
+      viewport: { width: window.innerWidth, height: window.innerHeight },
+      outerScrollLocked: rootScrollLocked,
+      panelScrolls: Boolean(panelMetrics && panelMetrics.scrollHeight > panelMetrics.clientHeight && afterPanelScroll > beforePanelScroll),
+      rootAfterScrollAttempt,
+      html,
+      body,
+      shell,
+      panel: panelMetrics
+    };
+  }, { panelSelector });
+}
+
+async function inspectHelpMarkdownRoute(page) {
+  return page.evaluate(async () => {
+    const workspace = document.querySelector('[data-view="workspace"]');
+    const gate = document.querySelector('[data-view="gate"]');
+    const help = document.querySelector('[data-view="help"]');
+    const helpContent = document.querySelector("#help-content");
+    const heading = helpContent?.querySelector("h1");
+    const renderedLists = helpContent?.querySelectorAll("li").length ?? 0;
+    const codeCount = helpContent?.querySelectorAll("code").length ?? 0;
+    const text = helpContent?.textContent ?? "";
+    const helpScroll = await (async () => {
+      if (!helpContent) return null;
+      helpContent.scrollTop = 0;
+      await new Promise((resolve) => requestAnimationFrame(resolve));
+      const before = helpContent.scrollTop;
+      helpContent.scrollTop = helpContent.scrollHeight;
+      await new Promise((resolve) => requestAnimationFrame(resolve));
+      return {
+        before,
+        after: helpContent.scrollTop,
+        clientHeight: helpContent.clientHeight,
+        scrollHeight: helpContent.scrollHeight,
+        overflowY: getComputedStyle(helpContent).overflowY
+      };
+    })();
+    const rootStillLocked =
+      getComputedStyle(document.documentElement).overflow === "hidden" &&
+      getComputedStyle(document.body).overflow === "hidden" &&
+      document.documentElement.scrollHeight <= document.documentElement.clientHeight + 2 &&
+      document.body.scrollHeight <= document.body.clientHeight + 2;
+    return {
+      hash: window.location.hash,
+      helpState: helpContent?.dataset.helpState ?? null,
+      workspaceHidden: workspace ? workspace.hidden : null,
+      gateHidden: gate ? gate.hidden : null,
+      helpHidden: help ? help.hidden : null,
+      heading: heading?.textContent?.trim() ?? null,
+      renderedLists,
+      codeCount,
+      hasRawMarkdownHeading: Boolean(helpContent?.textContent?.includes("# 云工作台内部使用说明")),
+      termsPresent:
+        ["左侧资源与功能导航", "Agent 对话与工作清单", "same-origin", "/v1", ":16666"].every((term) => text.includes(term)) &&
+        codeCount >= 8,
+      helpPanelScrolls: Boolean(helpScroll && helpScroll.scrollHeight > helpScroll.clientHeight && helpScroll.after > helpScroll.before),
+      rootStillLocked,
+      helpScroll,
+      nonDefaultMarkdownHelp:
+        window.location.hash === "#help" &&
+        workspace?.hidden === true &&
+        gate?.hidden === true &&
+        help?.hidden === false &&
+        helpContent?.dataset.helpState === "ready" &&
+        heading?.textContent?.trim() === "云工作台内部使用说明" &&
+        renderedLists >= 8 &&
+        codeCount >= 8 &&
+        !helpContent?.textContent?.includes("# 云工作台内部使用说明") &&
+        rootStillLocked &&
+        Boolean(helpScroll && helpScroll.scrollHeight > helpScroll.clientHeight && helpScroll.after > helpScroll.before)
+    };
+  });
+}
+
 function escapeRegExp(value) {
   return String(value).replace(/[.*+?^${}()|[\]\\]/gu, "\\$&");
 }
diff --git a/web/hwlab-cloud-web/scripts/check.mjs b/web/hwlab-cloud-web/scripts/check.mjs
index b4f8379a..543ecd37 100644
--- a/web/hwlab-cloud-web/scripts/check.mjs
+++ b/web/hwlab-cloud-web/scripts/check.mjs
@@ -199,6 +199,8 @@ assert.match(app, /return "workspace";/);
 assert.match(styles, /\.help-view\s*{[^}]*overflow:\s*hidden;/s);
 assert.match(styles, /\.help-panel\s*{[^}]*overflow:\s*hidden;/s);
 assert.match(styles, /\.help-content\s*{[^}]*overflow:\s*auto;/s);
+assert.match(styles, /body\s*>\s*\[data-app-shell\]\s*{[^}]*height:\s*100%;[^}]*overflow:\s*hidden;[^}]*overscroll-behavior:\s*contain;/s);
+assert.match(styles, /\.workbench-shell\s*{[^}]*height:\s*100dvh;[^}]*max-height:\s*100dvh;[^}]*overflow:\s*hidden;[^}]*overscroll-behavior:\s*contain;/s);
 assert.match(helpMarkdown, /^# 云工作台内部使用说明/m);
 for (const helpTerm of [
   "左侧资源与功能导航",
diff --git a/web/hwlab-cloud-web/styles.css b/web/hwlab-cloud-web/styles.css
index 153f6e5d..3e581917 100644
--- a/web/hwlab-cloud-web/styles.css
+++ b/web/hwlab-cloud-web/styles.css
@@ -42,7 +42,10 @@ body {
 }
 
 body > [data-app-shell] {
+  height: 100%;
   min-height: 0;
+  overflow: hidden;
+  overscroll-behavior: contain;
 }
 
 button,
@@ -66,11 +69,13 @@ ul {
 .workbench-shell {
   height: 100vh;
   height: 100dvh;
+  max-height: 100dvh;
   min-height: 0;
   display: grid;
   grid-template-columns: 92px 292px minmax(460px, 1fr) 366px;
   grid-template-rows: 1fr;
   overflow: hidden;
+  overscroll-behavior: contain;
   background: rgba(15, 17, 16, 0.88);
 }