diff --git a/design/10-review/process/16-mnote-web-runtime-module-maintainability-checklist-v1.md b/design/10-review/process/16-mnote-web-runtime-module-maintainability-checklist-v1.md
index 48ddd87e..6dc3852d 100644
--- a/design/10-review/process/16-mnote-web-runtime-module-maintainability-checklist-v1.md
+++ b/design/10-review/process/16-mnote-web-runtime-module-maintainability-checklist-v1.md
@@ -123,7 +123,7 @@ cargo test --manifest-path rust/Cargo.toml -p mnote-web --lib routes::tests::mno
 - [x] B2. `document-tiptap-conversion-runtime.js`：legacy block / inline content / marks 转 Tiptap document。
 - [ ] B3. `document-resource-tab-runtime.js`：resource tab registry、MRU、close guard、resource text/image/frame editor mount。
 - [ ] B4. `document-mindmap-host-runtime.js`：primary mindmap object shell、mindmap resource tab mount/unmount。
-- [ ] B5. `document-slash-position-runtime.js`：slash menu active root、positioning、mutation observer。
+- [x] B5. `document-slash-position-runtime.js`：slash menu active root、positioning、mutation observer。
 - [ ] B6. entrypoint 只负责读取 bootstrap、加载 runtime、装配各子模块。
 
 验收标准：
diff --git a/rust/crates/mnote-web/browser/document-editor-adapter-runtime.js b/rust/crates/mnote-web/browser/document-editor-adapter-runtime.js
index c33fb446..0ce3d0af 100644
--- a/rust/crates/mnote-web/browser/document-editor-adapter-runtime.js
+++ b/rust/crates/mnote-web/browser/document-editor-adapter-runtime.js
@@ -1,3 +1,9 @@
+import {
+  installGlobalSlashMenuPositioning,
+  markIntendedSlashRoot,
+  observeSlashMenuPosition,
+  scheduleSlashMenuPosition,
+} from './document-slash-position-runtime.js';
 import {
   buildPaneRuntime,
   clearSecondaryParams,
@@ -1950,225 +1956,8 @@ import {
     view.disconnectObserver = () => observer.disconnect();
   };
 
-  const activeEditorRootForSlashMenu = () => {
-    const selection = window.getSelection();
-    const anchorNode = selection?.anchorNode || null;
-    const anchorElement = anchorNode && anchorNode.nodeType === Node.ELEMENT_NODE
-      ? anchorNode
-      : anchorNode?.parentElement || null;
-    const roots = Array.from(document.querySelectorAll(ROOT_SELECTOR)).filter((node) => (
-      node instanceof HTMLElement
-        && node.offsetParent !== null
-        && node.getAttribute('data-mnote-side-target-unsupported') !== 'true'
-    ));
-    const intendedRoot = window.__mnoteIntendedSlashRoot instanceof HTMLElement
-      && roots.includes(window.__mnoteIntendedSlashRoot)
-      ? window.__mnoteIntendedSlashRoot
-      : null;
-    if (intendedRoot) return intendedRoot;
-    const focused = document.activeElement instanceof Element
-      ? roots.find((root) => root.contains(document.activeElement))
-      : null;
-    if (focused) return focused;
-    if (anchorElement instanceof Element) {
-      const activeRoot = roots.find((root) => root.contains(anchorElement));
-      if (activeRoot) return activeRoot;
-    }
-    return roots.find((root) => root.querySelector('.ProseMirror:focus-within')) || roots[0] || null;
-  };
-
-  const markIntendedSlashRoot = (entry) => {
-    const root = entry?.view?.runtimeDescriptor?.root;
-    if (!(root instanceof HTMLElement) || !root.isConnected) return;
-    window.__mnoteIntendedSlashRoot = root;
-    hideSlashMenusOutsideRoot(root);
-    scheduleSlashMenuPosition(root);
-  };
-
-  const slashMenuAnchorFromSelection = (root) => {
-    const currentBlockFromSelection = () => {
-      try {
-        const selection = window.getSelection();
-        const anchorNode = selection?.anchorNode || null;
-        const editor = root.querySelector('.ProseMirror');
-        const anchorElement = anchorNode && anchorNode.nodeType === Node.ELEMENT_NODE
-          ? anchorNode
-          : anchorNode?.parentElement || null;
-        if (!(editor instanceof HTMLElement) || !(anchorElement instanceof Element) || !editor.contains(anchorElement)) return null;
-        let current = anchorElement;
-        while (current && current.parentElement && current.parentElement !== editor) {
-          current = current.parentElement;
-        }
-        return current instanceof HTMLElement && current.parentElement === editor ? current : null;
-      } catch (_) {
-        return null;
-      }
-    };
-    const fallback = () => {
-      const editor = root.querySelector('.ProseMirror');
-      if (editor instanceof HTMLElement) {
-        const block = currentBlockFromSelection()
-          || Array.from(editor.children).find((node) => node instanceof HTMLElement && node.matches(':focus-within, .ProseMirror-selectednode'))
-          || Array.from(editor.children).find((node) => node instanceof HTMLElement && node.getBoundingClientRect().height > 0);
-        if (block instanceof HTMLElement) {
-          const rect = block.getBoundingClientRect();
-          return { top: rect.bottom + 8, left: rect.left, anchorTop: rect.top };
-        }
-      }
-      const rect = root.getBoundingClientRect();
-      return { top: rect.top + 24, left: rect.left + 24, anchorTop: rect.top + 24 };
-    };
-    try {
-      const selection = window.getSelection();
-      if (!selection || selection.rangeCount <= 0) return fallback();
-      const anchorNode = selection.anchorNode;
-      if (anchorNode && !root.contains(anchorNode.nodeType === Node.ELEMENT_NODE ? anchorNode : anchorNode.parentElement)) {
-        return fallback();
-      }
-      const rect = selection.getRangeAt(0).getBoundingClientRect();
-      if (rect && (rect.top > 0 || rect.left > 0 || rect.height > 0)) {
-        return { top: rect.bottom + 8, left: rect.left, anchorTop: rect.top };
-      }
-    } catch (_) {}
-    return fallback();
-  };
-
-  const setSlashMenuInactive = (menu, inactive) => {
-    if (!(menu instanceof HTMLElement)) return;
-    if (inactive) {
-      if (menu.getAttribute('data-mnote-slash-inactive') !== 'true') {
-        menu.setAttribute('data-mnote-slash-inactive', 'true');
-      }
-      if (menu.style.display !== 'none') menu.style.display = 'none';
-      return;
-    }
-    if (menu.getAttribute('data-mnote-slash-inactive') === 'true') {
-      menu.removeAttribute('data-mnote-slash-inactive');
-    }
-    if (menu.style.display === 'none') menu.style.display = '';
-  };
-
-  const setSlashMenuStyle = (menu, property, value) => {
-    if (!(menu instanceof HTMLElement)) return;
-    if (menu.style[property] !== value) menu.style[property] = value;
-  };
-
-  const setSlashMenuAttribute = (menu, name, value) => {
-    if (!(menu instanceof HTMLElement)) return;
-    if (menu.getAttribute(name) !== value) menu.setAttribute(name, value);
-  };
-
-  const hideSlashMenusOutsideRoot = (activeRoot) => {
-    document.querySelectorAll(`${ROOT_SELECTOR} [data-testid="mnote-leptos-tiptap-slash-menu"]`).forEach((menu) => {
-      const root = menu.closest(ROOT_SELECTOR);
-      if (root !== activeRoot) setSlashMenuInactive(menu, true);
-    });
-  };
-
-  const positionSlashMenuForRoot = (root) => {
-    const activeRoot = activeEditorRootForSlashMenu();
-    if (!(root instanceof HTMLElement)) root = activeRoot;
-    if (!(root instanceof HTMLElement)) return;
-    if (activeRoot instanceof HTMLElement && root !== activeRoot) {
-      const inactiveMenu = root.querySelector('[data-testid="mnote-leptos-tiptap-slash-menu"]');
-      setSlashMenuInactive(inactiveMenu, true);
-      hideSlashMenusOutsideRoot(activeRoot);
-      return;
-    }
-    hideSlashMenusOutsideRoot(root);
-    const menu = root.querySelector('[data-testid="mnote-leptos-tiptap-slash-menu"]');
-    if (!(menu instanceof HTMLElement)) return;
-    setSlashMenuInactive(menu, false);
-    const anchor = slashMenuAnchorFromSelection(root);
-    const gap = 8;
-    const menuWidth = Math.min(316, Math.max(160, window.innerWidth - 16));
-    const menuHeight = Math.min(430, Math.max(120, window.innerHeight - 16));
-    const left = Math.min(Math.max(gap, anchor.left), Math.max(gap, window.innerWidth - menuWidth - gap));
-    const belowTop = Math.min(Math.max(gap, anchor.top), Math.max(gap, window.innerHeight - 120));
-    let top = belowTop + menuHeight > window.innerHeight - gap
-      ? Math.min(Math.max(gap, anchor.anchorTop - menuHeight - gap), Math.max(gap, window.innerHeight - 120))
-      : belowTop;
-    const mindmap = document.querySelector('[data-testid="mnote-mindmap-editor-root"]');
-    if (mindmap instanceof HTMLElement) {
-      const mindmapRect = mindmap.getBoundingClientRect();
-      const overlapsMindmap = top < mindmapRect.bottom && top + menuHeight > mindmapRect.top;
-      if (overlapsMindmap && mindmapRect.bottom > window.innerHeight - 48) {
-        top = Math.max(top, Math.max(gap, window.innerHeight - menuHeight - gap));
-      } else if (overlapsMindmap && mindmapRect.bottom + menuHeight + gap <= window.innerHeight) {
-        top = mindmapRect.bottom + gap;
-      }
-    }
-    setSlashMenuStyle(menu, 'position', 'fixed');
-    setSlashMenuStyle(menu, 'zIndex', '130');
-    setSlashMenuStyle(menu, 'left', `${Math.round(left)}px`);
-    setSlashMenuStyle(menu, 'top', `${Math.round(top)}px`);
-    setSlashMenuStyle(menu, 'width', `min(316px, calc(100vw - 16px))`);
-    setSlashMenuStyle(menu, 'maxHeight', `min(430px, calc(100vh - 16px))`);
-    setSlashMenuAttribute(menu, 'data-mnote-slash-positioned', 'host');
-  };
-
-  let pendingSlashMenuPositionFrame = 0;
-  let pendingSlashMenuPositionRoot = null;
-  const scheduleSlashMenuPosition = (root) => {
-    if (root instanceof HTMLElement) pendingSlashMenuPositionRoot = root;
-    if (pendingSlashMenuPositionFrame) return;
-    pendingSlashMenuPositionFrame = window.requestAnimationFrame(() => {
-      const targetRoot = pendingSlashMenuPositionRoot;
-      pendingSlashMenuPositionFrame = 0;
-      pendingSlashMenuPositionRoot = null;
-      positionSlashMenuForRoot(targetRoot);
-    });
-  };
-
-  const shouldReactToSlashMenuMutation = (records, root) => {
-    if (!Array.isArray(records) || !(root instanceof HTMLElement)) return false;
-    return records.some((record) => {
-      const target = record && record.target instanceof HTMLElement ? record.target : null;
-      if (!target || !root.contains(target) && target !== root) return false;
-      if (record.type === 'attributes') {
-        return record.attributeName !== 'style' && record.attributeName !== 'data-mnote-slash-positioned' && record.attributeName !== 'data-mnote-slash-inactive';
-      }
-      if (record.type === 'childList') {
-        return Array.from(record.addedNodes || []).some((node) => node instanceof HTMLElement && node.closest('[data-testid="mnote-leptos-tiptap-slash-menu"]'))
-          || Array.from(record.removedNodes || []).some((node) => node instanceof HTMLElement && node.closest('[data-testid="mnote-leptos-tiptap-slash-menu"]'));
-      }
-      return true;
-    });
-  };
-
-  const scheduleGlobalSlashMenuPosition = () => {
-    scheduleSlashMenuPosition(activeEditorRootForSlashMenu());
-  };
-
-  const installGlobalSlashMenuPositioning = () => {
-    if (window.__MNOTE_SLASH_MENU_POSITIONING_INSTALLED__) return;
-    window.__MNOTE_SLASH_MENU_POSITIONING_INSTALLED__ = true;
-    if (typeof MutationObserver === 'function' && document.body instanceof HTMLElement) {
-      const observer = new MutationObserver(() => scheduleGlobalSlashMenuPosition());
-      observer.observe(document.body, { childList: true, subtree: true, attributes: true, attributeFilter: ['style', 'class', 'hidden'] });
-    }
-    document.addEventListener('keydown', (event) => {
-      if (event.key === '/') scheduleGlobalSlashMenuPosition();
-    }, true);
-    document.addEventListener('selectionchange', () => scheduleGlobalSlashMenuPosition(), true);
-    window.addEventListener('resize', scheduleGlobalSlashMenuPosition);
-    window.addEventListener('scroll', scheduleGlobalSlashMenuPosition, true);
-  };
-
   installGlobalSlashMenuPositioning();
 
-  const observeSlashMenuPosition = (view) => {
-    const root = view.runtimeDescriptor.root;
-    if (!(root instanceof HTMLElement) || typeof MutationObserver !== 'function') return;
-    const observer = new MutationObserver((records) => {
-      if (!view.disposed && shouldReactToSlashMenuMutation(records, root)) {
-        scheduleSlashMenuPosition(root);
-      }
-    });
-    observer.observe(root, { childList: true, subtree: true, attributes: true, attributeFilter: ['style', 'hidden', 'class', 'data-mnote-slash-positioned', 'data-mnote-slash-inactive'] });
-    view.disconnectSlashObserver = () => observer.disconnect();
-  };
-
   const createEditorViewBinding = (session, runtime, runtimeDescriptor) => {
     cancelDocumentSessionRelease(session);
     const view = {
diff --git a/rust/crates/mnote-web/browser/document-slash-position-runtime.js b/rust/crates/mnote-web/browser/document-slash-position-runtime.js
new file mode 100644
index 00000000..7bea46f0
--- /dev/null
+++ b/rust/crates/mnote-web/browser/document-slash-position-runtime.js
@@ -0,0 +1,218 @@
+const ROOT_SELECTOR = '[data-testid="mnote-leptos-tiptap-island-editor-root"]';
+
+export const activeEditorRootForSlashMenu = () => {
+  const selection = window.getSelection();
+  const anchorNode = selection?.anchorNode || null;
+  const anchorElement = anchorNode && anchorNode.nodeType === Node.ELEMENT_NODE
+    ? anchorNode
+    : anchorNode?.parentElement || null;
+  const roots = Array.from(document.querySelectorAll(ROOT_SELECTOR)).filter((node) => (
+    node instanceof HTMLElement
+      && node.offsetParent !== null
+      && node.getAttribute('data-mnote-side-target-unsupported') !== 'true'
+  ));
+  const intendedRoot = window.__mnoteIntendedSlashRoot instanceof HTMLElement
+    && roots.includes(window.__mnoteIntendedSlashRoot)
+    ? window.__mnoteIntendedSlashRoot
+    : null;
+  if (intendedRoot) return intendedRoot;
+  const focused = document.activeElement instanceof Element
+    ? roots.find((root) => root.contains(document.activeElement))
+    : null;
+  if (focused) return focused;
+  if (anchorElement instanceof Element) {
+    const activeRoot = roots.find((root) => root.contains(anchorElement));
+    if (activeRoot) return activeRoot;
+  }
+  return roots.find((root) => root.querySelector('.ProseMirror:focus-within')) || roots[0] || null;
+};
+
+export const markIntendedSlashRoot = (entry) => {
+  const root = entry?.view?.runtimeDescriptor?.root;
+  if (!(root instanceof HTMLElement) || !root.isConnected) return;
+  window.__mnoteIntendedSlashRoot = root;
+  hideSlashMenusOutsideRoot(root);
+  scheduleSlashMenuPosition(root);
+};
+
+export const slashMenuAnchorFromSelection = (root) => {
+  const currentBlockFromSelection = () => {
+    try {
+      const selection = window.getSelection();
+      const anchorNode = selection?.anchorNode || null;
+      const editor = root.querySelector('.ProseMirror');
+      const anchorElement = anchorNode && anchorNode.nodeType === Node.ELEMENT_NODE
+        ? anchorNode
+        : anchorNode?.parentElement || null;
+      if (!(editor instanceof HTMLElement) || !(anchorElement instanceof Element) || !editor.contains(anchorElement)) return null;
+      let current = anchorElement;
+      while (current && current.parentElement && current.parentElement !== editor) {
+        current = current.parentElement;
+      }
+      return current instanceof HTMLElement && current.parentElement === editor ? current : null;
+    } catch (_) {
+      return null;
+    }
+  };
+  const fallback = () => {
+    const editor = root.querySelector('.ProseMirror');
+    if (editor instanceof HTMLElement) {
+      const block = currentBlockFromSelection()
+        || Array.from(editor.children).find((node) => node instanceof HTMLElement && node.matches(':focus-within, .ProseMirror-selectednode'))
+        || Array.from(editor.children).find((node) => node instanceof HTMLElement && node.getBoundingClientRect().height > 0);
+      if (block instanceof HTMLElement) {
+        const rect = block.getBoundingClientRect();
+        return { top: rect.bottom + 8, left: rect.left, anchorTop: rect.top };
+      }
+    }
+    const rect = root.getBoundingClientRect();
+    return { top: rect.top + 24, left: rect.left + 24, anchorTop: rect.top + 24 };
+  };
+  try {
+    const selection = window.getSelection();
+    if (!selection || selection.rangeCount <= 0) return fallback();
+    const anchorNode = selection.anchorNode;
+    if (anchorNode && !root.contains(anchorNode.nodeType === Node.ELEMENT_NODE ? anchorNode : anchorNode.parentElement)) {
+      return fallback();
+    }
+    const rect = selection.getRangeAt(0).getBoundingClientRect();
+    if (rect && (rect.top > 0 || rect.left > 0 || rect.height > 0)) {
+      return { top: rect.bottom + 8, left: rect.left, anchorTop: rect.top };
+    }
+  } catch (_) {}
+  return fallback();
+};
+
+export const setSlashMenuInactive = (menu, inactive) => {
+  if (!(menu instanceof HTMLElement)) return;
+  if (inactive) {
+    if (menu.getAttribute('data-mnote-slash-inactive') !== 'true') {
+      menu.setAttribute('data-mnote-slash-inactive', 'true');
+    }
+    if (menu.style.display !== 'none') menu.style.display = 'none';
+    return;
+  }
+  if (menu.getAttribute('data-mnote-slash-inactive') === 'true') {
+    menu.removeAttribute('data-mnote-slash-inactive');
+  }
+  if (menu.style.display === 'none') menu.style.display = '';
+};
+
+export const setSlashMenuStyle = (menu, property, value) => {
+  if (!(menu instanceof HTMLElement)) return;
+  if (menu.style[property] !== value) menu.style[property] = value;
+};
+
+export const setSlashMenuAttribute = (menu, name, value) => {
+  if (!(menu instanceof HTMLElement)) return;
+  if (menu.getAttribute(name) !== value) menu.setAttribute(name, value);
+};
+
+export const hideSlashMenusOutsideRoot = (activeRoot) => {
+  document.querySelectorAll(`${ROOT_SELECTOR} [data-testid="mnote-leptos-tiptap-slash-menu"]`).forEach((menu) => {
+    const root = menu.closest(ROOT_SELECTOR);
+    if (root !== activeRoot) setSlashMenuInactive(menu, true);
+  });
+};
+
+export const positionSlashMenuForRoot = (root) => {
+  const activeRoot = activeEditorRootForSlashMenu();
+  if (!(root instanceof HTMLElement)) root = activeRoot;
+  if (!(root instanceof HTMLElement)) return;
+  if (activeRoot instanceof HTMLElement && root !== activeRoot) {
+    const inactiveMenu = root.querySelector('[data-testid="mnote-leptos-tiptap-slash-menu"]');
+    setSlashMenuInactive(inactiveMenu, true);
+    hideSlashMenusOutsideRoot(activeRoot);
+    return;
+  }
+  hideSlashMenusOutsideRoot(root);
+  const menu = root.querySelector('[data-testid="mnote-leptos-tiptap-slash-menu"]');
+  if (!(menu instanceof HTMLElement)) return;
+  setSlashMenuInactive(menu, false);
+  const anchor = slashMenuAnchorFromSelection(root);
+  const gap = 8;
+  const menuWidth = Math.min(316, Math.max(160, window.innerWidth - 16));
+  const menuHeight = Math.min(430, Math.max(120, window.innerHeight - 16));
+  const left = Math.min(Math.max(gap, anchor.left), Math.max(gap, window.innerWidth - menuWidth - gap));
+  const belowTop = Math.min(Math.max(gap, anchor.top), Math.max(gap, window.innerHeight - 120));
+  let top = belowTop + menuHeight > window.innerHeight - gap
+    ? Math.min(Math.max(gap, anchor.anchorTop - menuHeight - gap), Math.max(gap, window.innerHeight - 120))
+    : belowTop;
+  const mindmap = document.querySelector('[data-testid="mnote-mindmap-editor-root"]');
+  if (mindmap instanceof HTMLElement) {
+    const mindmapRect = mindmap.getBoundingClientRect();
+    const overlapsMindmap = top < mindmapRect.bottom && top + menuHeight > mindmapRect.top;
+    if (overlapsMindmap && mindmapRect.bottom > window.innerHeight - 48) {
+      top = Math.max(top, Math.max(gap, window.innerHeight - menuHeight - gap));
+    } else if (overlapsMindmap && mindmapRect.bottom + menuHeight + gap <= window.innerHeight) {
+      top = mindmapRect.bottom + gap;
+    }
+  }
+  setSlashMenuStyle(menu, 'position', 'fixed');
+  setSlashMenuStyle(menu, 'zIndex', '130');
+  setSlashMenuStyle(menu, 'left', `${Math.round(left)}px`);
+  setSlashMenuStyle(menu, 'top', `${Math.round(top)}px`);
+  setSlashMenuStyle(menu, 'width', `min(316px, calc(100vw - 16px))`);
+  setSlashMenuStyle(menu, 'maxHeight', `min(430px, calc(100vh - 16px))`);
+  setSlashMenuAttribute(menu, 'data-mnote-slash-positioned', 'host');
+};
+
+export let pendingSlashMenuPositionFrame = 0;
+export let pendingSlashMenuPositionRoot = null;
+export const scheduleSlashMenuPosition = (root) => {
+  if (root instanceof HTMLElement) pendingSlashMenuPositionRoot = root;
+  if (pendingSlashMenuPositionFrame) return;
+  pendingSlashMenuPositionFrame = window.requestAnimationFrame(() => {
+    const targetRoot = pendingSlashMenuPositionRoot;
+    pendingSlashMenuPositionFrame = 0;
+    pendingSlashMenuPositionRoot = null;
+    positionSlashMenuForRoot(targetRoot);
+  });
+};
+
+export const shouldReactToSlashMenuMutation = (records, root) => {
+  if (!Array.isArray(records) || !(root instanceof HTMLElement)) return false;
+  return records.some((record) => {
+    const target = record && record.target instanceof HTMLElement ? record.target : null;
+    if (!target || !root.contains(target) && target !== root) return false;
+    if (record.type === 'attributes') {
+      return record.attributeName !== 'style' && record.attributeName !== 'data-mnote-slash-positioned' && record.attributeName !== 'data-mnote-slash-inactive';
+    }
+    if (record.type === 'childList') {
+      return Array.from(record.addedNodes || []).some((node) => node instanceof HTMLElement && node.closest('[data-testid="mnote-leptos-tiptap-slash-menu"]'))
+        || Array.from(record.removedNodes || []).some((node) => node instanceof HTMLElement && node.closest('[data-testid="mnote-leptos-tiptap-slash-menu"]'));
+    }
+    return true;
+  });
+};
+
+export const scheduleGlobalSlashMenuPosition = () => {
+  scheduleSlashMenuPosition(activeEditorRootForSlashMenu());
+};
+
+export const installGlobalSlashMenuPositioning = () => {
+  if (window.__MNOTE_SLASH_MENU_POSITIONING_INSTALLED__) return;
+  window.__MNOTE_SLASH_MENU_POSITIONING_INSTALLED__ = true;
+  if (typeof MutationObserver === 'function' && document.body instanceof HTMLElement) {
+    const observer = new MutationObserver(() => scheduleGlobalSlashMenuPosition());
+    observer.observe(document.body, { childList: true, subtree: true, attributes: true, attributeFilter: ['style', 'class', 'hidden'] });
+  }
+  document.addEventListener('keydown', (event) => {
+    if (event.key === '/') scheduleGlobalSlashMenuPosition();
+  }, true);
+  document.addEventListener('selectionchange', () => scheduleGlobalSlashMenuPosition(), true);
+  window.addEventListener('resize', scheduleGlobalSlashMenuPosition);
+  window.addEventListener('scroll', scheduleGlobalSlashMenuPosition, true);
+};
+
+export const observeSlashMenuPosition = (view) => {
+  const root = view.runtimeDescriptor.root;
+  if (!(root instanceof HTMLElement) || typeof MutationObserver !== 'function') return;
+  const observer = new MutationObserver((records) => {
+    if (!view.disposed && shouldReactToSlashMenuMutation(records, root)) {
+      scheduleSlashMenuPosition(root);
+    }
+  });
+  observer.observe(root, { childList: true, subtree: true, attributes: true, attributeFilter: ['style', 'hidden', 'class', 'data-mnote-slash-positioned', 'data-mnote-slash-inactive'] });
+  view.disconnectSlashObserver = () => observer.disconnect();
+};
diff --git a/rust/crates/mnote-web/src/routes/mod.rs b/rust/crates/mnote-web/src/routes/mod.rs
index 700664de..130f4d39 100644
--- a/rust/crates/mnote-web/src/routes/mod.rs
+++ b/rust/crates/mnote-web/src/routes/mod.rs
@@ -146,6 +146,10 @@ pub fn build_router(state: AppState) -> Router {
             "/api/mnote-browser-runtime/document-pane-runtime.js",
             get(web_shell::document_pane_runtime_asset),
         )
+        .route(
+            "/api/mnote-browser-runtime/document-slash-position-runtime.js",
+            get(web_shell::document_slash_position_runtime_asset),
+        )
         .route(
             "/api/mnote-browser-runtime/document-tiptap-conversion-runtime.js",
             get(web_shell::document_tiptap_conversion_runtime_asset),
@@ -568,6 +572,7 @@ mod tests {
             "/api/mnote-browser-runtime/tree-shell-runtime.js",
             "/api/mnote-browser-runtime/document-conflict-panel-runtime.js",
             "/api/mnote-browser-runtime/document-pane-runtime.js",
+            "/api/mnote-browser-runtime/document-slash-position-runtime.js",
             "/api/mnote-browser-runtime/document-tiptap-conversion-runtime.js",
             "/api/mnote-browser-runtime/document-editor-adapter-runtime.js",
         ] {
diff --git a/rust/crates/mnote-web/src/routes/web_shell.rs b/rust/crates/mnote-web/src/routes/web_shell.rs
index b1c495a8..d2abeb5c 100644
--- a/rust/crates/mnote-web/src/routes/web_shell.rs
+++ b/rust/crates/mnote-web/src/routes/web_shell.rs
@@ -869,6 +869,20 @@ pub async fn document_pane_runtime_asset() -> Response {
         .unwrap_or_else(|_| Response::new(Body::empty()))
 }
 
+pub async fn document_slash_position_runtime_asset() -> Response {
+    const JS: &str = include_str!("../../browser/document-slash-position-runtime.js");
+    Response::builder()
+        .status(StatusCode::OK)
+        .header(
+            header::CONTENT_TYPE,
+            "application/javascript; charset=utf-8",
+        )
+        .header(header::CACHE_CONTROL, "no-store")
+        .header(HEADER_MNOTE_WEB_OWNER, "mnote-web")
+        .body(Body::from(JS))
+        .unwrap_or_else(|_| Response::new(Body::empty()))
+}
+
 pub async fn document_tiptap_conversion_runtime_asset() -> Response {
     const JS: &str = include_str!("../../browser/document-tiptap-conversion-runtime.js");
     Response::builder()
@@ -1307,6 +1321,8 @@ mod tests {
     const DOCUMENT_EDITOR_ADAPTER_RUNTIME_JS: &str =
         include_str!("../../browser/document-editor-adapter-runtime.js");
     const DOCUMENT_PANE_RUNTIME_JS: &str = include_str!("../../browser/document-pane-runtime.js");
+    const DOCUMENT_SLASH_POSITION_RUNTIME_JS: &str =
+        include_str!("../../browser/document-slash-position-runtime.js");
     const DOCUMENT_TIPTAP_CONVERSION_RUNTIME_JS: &str =
         include_str!("../../browser/document-tiptap-conversion-runtime.js");
 
@@ -1565,21 +1581,24 @@ mod tests {
         assert!(!html
             .contains("nodes.pageTab?.getAttribute?.('data-document-id') || currentDocumentId()"));
         assert!(runtime.contains("runtime.default({ module_or_path: wasmUrl })"));
-        assert!(runtime.contains("positionSlashMenuForRoot"));
-        assert!(runtime.contains("setSlashMenuStyle(menu, 'position', 'fixed');"));
+        let slash_runtime = DOCUMENT_SLASH_POSITION_RUNTIME_JS;
+        assert!(slash_runtime.contains("positionSlashMenuForRoot"));
+        assert!(slash_runtime.contains("setSlashMenuStyle(menu, 'position', 'fixed');"));
         assert!(runtime.contains("installGlobalSlashMenuPositioning();"));
-        assert!(runtime.contains("data-mnote-slash-positioned', 'host'"));
-        assert!(runtime.contains(
+        assert!(slash_runtime.contains("data-mnote-slash-positioned', 'host'"));
+        assert!(slash_runtime.contains(
             "const menu = root.querySelector('[data-testid=\"mnote-leptos-tiptap-slash-menu\"]');"
         ));
-        assert!(runtime.contains("const setSlashMenuInactive = (menu, inactive) =>"));
-        assert!(runtime.contains("const hideSlashMenusOutsideRoot = (activeRoot) =>"));
-        assert!(runtime.contains("data-mnote-slash-inactive"));
-        assert!(runtime.contains("if (activeRoot instanceof HTMLElement && root !== activeRoot)"));
+        assert!(slash_runtime.contains("const setSlashMenuInactive = (menu, inactive) =>"));
+        assert!(slash_runtime.contains("const hideSlashMenusOutsideRoot = (activeRoot) =>"));
+        assert!(slash_runtime.contains("data-mnote-slash-inactive"));
+        assert!(
+            slash_runtime.contains("if (activeRoot instanceof HTMLElement && root !== activeRoot)")
+        );
         assert!(!runtime.contains(
             "|| document.querySelector('[data-testid=\"mnote-leptos-tiptap-slash-menu\"]')"
         ));
-        assert!(runtime.contains("data-mnote-side-target-unsupported') !== 'true'"));
+        assert!(slash_runtime.contains("data-mnote-side-target-unsupported') !== 'true'"));
         assert!(
             runtime.contains("runtimeDescriptor.root.addEventListener(STATE_EVENT, view.onState);")
         );
@@ -2059,6 +2078,9 @@ mod tests {
         assert!(DOCUMENT_EDITOR_ADAPTER_RUNTIME_JS.contains("document-pane-runtime.js"));
         assert!(DOCUMENT_PANE_RUNTIME_JS.contains("openDocumentInSecondaryPane"));
         assert!(DOCUMENT_PANE_RUNTIME_JS.contains("buildPaneRuntime"));
+        assert!(DOCUMENT_EDITOR_ADAPTER_RUNTIME_JS.contains("document-slash-position-runtime.js"));
+        assert!(DOCUMENT_SLASH_POSITION_RUNTIME_JS.contains("observeSlashMenuPosition"));
+        assert!(DOCUMENT_SLASH_POSITION_RUNTIME_JS.contains("scheduleSlashMenuPosition"));
         assert!(
             DOCUMENT_EDITOR_ADAPTER_RUNTIME_JS.contains("document-tiptap-conversion-runtime.js")
         );