diff --git a/backend/app/core/deps.py b/backend/app/core/deps.py
index d5c2ebd6..0505948a 100644
--- a/backend/app/core/deps.py
+++ b/backend/app/core/deps.py
@@ -1,7 +1,7 @@
 from typing import Annotated, AsyncGenerator, Callable, Iterable
 import uuid
 
-from fastapi import Depends, HTTPException, status
+from fastapi import Depends, HTTPException, Request, status
 from pydantic import ValidationError
 from sqlalchemy.ext.asyncio import AsyncSession
 
@@ -139,11 +139,71 @@ async def get_cra_site_scope(
 def require_study_not_locked():
     """检查项目是否被锁定，如果锁定则拒绝所有修改请求"""
     from app.crud import study as study_crud
+    from app.crud import faq_category as faq_category_crud
+    from app.crud import faq_item as faq_item_crud
+
+    async def resolve_study_id(request: Request, db: AsyncSession) -> uuid.UUID:
+        raw_study_id = request.path_params.get("study_id") or request.query_params.get("study_id")
+        if raw_study_id:
+            try:
+                return uuid.UUID(str(raw_study_id))
+            except ValueError as exc:
+                raise HTTPException(
+                    status_code=status.HTTP_422_UNPROCESSABLE_ENTITY,
+                    detail="项目 ID 格式错误",
+                ) from exc
+
+        try:
+            body = await request.json()
+        except Exception:
+            body = None
+        if isinstance(body, dict) and body.get("study_id"):
+            try:
+                return uuid.UUID(str(body["study_id"]))
+            except ValueError as exc:
+                raise HTTPException(
+                    status_code=status.HTTP_422_UNPROCESSABLE_ENTITY,
+                    detail="项目 ID 格式错误",
+                ) from exc
+
+        raw_category_id = request.path_params.get("category_id")
+        if raw_category_id:
+            try:
+                category_id = uuid.UUID(str(raw_category_id))
+            except ValueError as exc:
+                raise HTTPException(
+                    status_code=status.HTTP_422_UNPROCESSABLE_ENTITY,
+                    detail="分类 ID 格式错误",
+                ) from exc
+            category = await faq_category_crud.get_category(db, category_id)
+            if not category or not category.study_id:
+                raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="分类不存在")
+            return category.study_id
+
+        raw_item_id = request.path_params.get("item_id")
+        if raw_item_id:
+            try:
+                item_id = uuid.UUID(str(raw_item_id))
+            except ValueError as exc:
+                raise HTTPException(
+                    status_code=status.HTTP_422_UNPROCESSABLE_ENTITY,
+                    detail="FAQ ID 格式错误",
+                ) from exc
+            item = await faq_item_crud.get_item(db, item_id)
+            if not item or not item.study_id:
+                raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="FAQ 不存在")
+            return item.study_id
+
+        raise HTTPException(
+            status_code=status.HTTP_422_UNPROCESSABLE_ENTITY,
+            detail="缺少项目 ID",
+        )
     
     async def dependency(
-        study_id: uuid.UUID,
+        request: Request,
         db: AsyncSession = Depends(get_db_session),
     ):
+        study_id = await resolve_study_id(request, db)
         study = await study_crud.get(db, study_id)
         if not study:
             raise HTTPException(
diff --git a/backend/app/main.py b/backend/app/main.py
index 118b273d..28304e0d 100644
--- a/backend/app/main.py
+++ b/backend/app/main.py
@@ -15,7 +15,6 @@ from app.core.exceptions import register_exception_handlers
 from app.crud.user import ensure_admin_exists
 from app.db.base import Base
 from app.db.session import SessionLocal, engine
-from app.services.fee_seed import seed_demo_fees
 from app.services.visit_scheduler import run_daily_lost_visit_job
 
 logger = logging.getLogger("ctms.setup_config")
@@ -38,7 +37,6 @@ async def lifespan(_: FastAPI):
             await conn.run_sync(Base.metadata.create_all)
         async with SessionLocal() as session:
             await ensure_admin_exists(session)
-            await seed_demo_fees(session)
     yield
     stop_event.set()
     await scheduler_task
diff --git a/backend/tests/test_app_startup.py b/backend/tests/test_app_startup.py
new file mode 100644
index 00000000..f31f4bb0
--- /dev/null
+++ b/backend/tests/test_app_startup.py
@@ -0,0 +1,78 @@
+from contextlib import asynccontextmanager
+from unittest.mock import AsyncMock
+
+import pytest
+from fastapi import FastAPI
+
+from app import main
+
+
+class _DummyTask:
+    def __init__(self):
+        self.awaited = False
+
+    def __await__(self):
+        async def _wait():
+            self.awaited = True
+
+        return _wait().__await__()
+
+
+class _DummySession:
+    async def __aenter__(self):
+        return self
+
+    async def __aexit__(self, exc_type, exc, tb):
+        return False
+
+
+class _DummyBegin:
+    async def __aenter__(self):
+        return self
+
+    async def __aexit__(self, exc_type, exc, tb):
+        return False
+
+    async def run_sync(self, fn):
+        return None
+
+
+class _DummyEngine:
+    def begin(self):
+        return _DummyBegin()
+
+
+@pytest.mark.asyncio
+async def test_development_startup_does_not_seed_demo_fees(monkeypatch):
+    ensure_admin_exists = AsyncMock()
+    seed_demo_fees = AsyncMock()
+    create_all = AsyncMock()
+    legacy_pk = AsyncMock()
+    scheduler_task = _DummyTask()
+
+    async def fake_scheduler(stop_event):
+        return None
+
+    def fake_create_task(coroutine):
+        coroutine.close()
+        return scheduler_task
+
+    @asynccontextmanager
+    async def fake_session_local():
+        yield _DummySession()
+
+    monkeypatch.setattr(main.settings, "ENV", "development")
+    monkeypatch.setattr(main, "ensure_admin_exists", ensure_admin_exists)
+    monkeypatch.setattr(main, "seed_demo_fees", seed_demo_fees, raising=False)
+    monkeypatch.setattr(main, "run_daily_lost_visit_job", fake_scheduler)
+    monkeypatch.setattr(main.asyncio, "create_task", fake_create_task)
+    monkeypatch.setattr(main, "engine", _DummyEngine())
+    monkeypatch.setattr(main, "SessionLocal", fake_session_local)
+    monkeypatch.setattr(main, "_ensure_legacy_primary_keys", legacy_pk)
+    monkeypatch.setattr(main.Base.metadata, "create_all", create_all)
+
+    async with main.lifespan(FastAPI()):
+        pass
+
+    ensure_admin_exists.assert_awaited_once()
+    seed_demo_fees.assert_not_awaited()
diff --git a/backend/tests/test_study_lock_dependency.py b/backend/tests/test_study_lock_dependency.py
new file mode 100644
index 00000000..805df935
--- /dev/null
+++ b/backend/tests/test_study_lock_dependency.py
@@ -0,0 +1,105 @@
+import uuid
+
+import pytest
+from fastapi import HTTPException
+from starlette.requests import Request
+
+from app.core import deps
+
+
+class _Study:
+    def __init__(self, study_id: uuid.UUID, is_locked: bool = False):
+        self.id = study_id
+        self.is_locked = is_locked
+
+
+class _Category:
+    def __init__(self, study_id: uuid.UUID | None):
+        self.study_id = study_id
+
+
+class _FaqItem:
+    def __init__(self, study_id: uuid.UUID | None):
+        self.study_id = study_id
+
+
+def _make_request(*, method: str = "POST", path: str = "/", query_string: bytes = b"", json_body: bytes = b"", path_params=None):
+    async def receive():
+        return {"type": "http.request", "body": json_body, "more_body": False}
+
+    scope = {
+        "type": "http",
+        "http_version": "1.1",
+        "method": method,
+        "path": path,
+        "raw_path": path.encode(),
+        "query_string": query_string,
+        "headers": [(b"content-type", b"application/json")],
+        "path_params": path_params or {},
+    }
+    return Request(scope, receive)
+
+
+@pytest.mark.asyncio
+async def test_require_study_not_locked_accepts_study_id_from_request_body(monkeypatch):
+    study_id = uuid.uuid4()
+
+    async def fake_get(_db, requested_study_id):
+        return _Study(requested_study_id, is_locked=False)
+
+    monkeypatch.setattr("app.crud.study.get", fake_get)
+
+    dependency = deps.require_study_not_locked()
+    request = _make_request(json_body=f'{{"study_id":"{study_id}"}}'.encode())
+
+    study = await dependency(request=request, db=object())
+
+    assert study.id == study_id
+
+
+@pytest.mark.asyncio
+async def test_require_study_not_locked_resolves_study_id_from_category_path(monkeypatch):
+    study_id = uuid.uuid4()
+    category_id = uuid.uuid4()
+
+    async def fake_get_category(_db, requested_category_id):
+        assert requested_category_id == category_id
+        return _Category(study_id)
+
+    async def fake_get_study(_db, requested_study_id):
+        return _Study(requested_study_id, is_locked=False)
+
+    monkeypatch.setattr("app.crud.faq_category.get_category", fake_get_category)
+    monkeypatch.setattr("app.crud.study.get", fake_get_study)
+
+    dependency = deps.require_study_not_locked()
+    request = _make_request(path=f"/api/v1/faqs/categories/{category_id}", path_params={"category_id": str(category_id)})
+
+    study = await dependency(request=request, db=object())
+
+    assert study.id == study_id
+
+
+@pytest.mark.asyncio
+async def test_require_study_not_locked_rejects_locked_study_resolved_from_item_path(monkeypatch):
+    study_id = uuid.uuid4()
+    item_id = uuid.uuid4()
+
+    async def fake_get_item(_db, requested_item_id):
+        assert requested_item_id == item_id
+        return _FaqItem(study_id)
+
+    async def fake_get_study(_db, requested_study_id):
+        return _Study(requested_study_id, is_locked=True)
+
+    monkeypatch.setattr("app.crud.faq_item.get_item", fake_get_item)
+    monkeypatch.setattr("app.crud.study.get", fake_get_study)
+
+    dependency = deps.require_study_not_locked()
+    request = _make_request(path=f"/api/v1/faqs/{item_id}", path_params={"item_id": str(item_id)})
+
+    with pytest.raises(HTTPException) as exc_info:
+        await dependency(request=request, db=object())
+
+    assert exc_info.value.status_code == 403
+    assert "项目已锁定" in exc_info.value.detail
diff --git a/docs/plans/2026-03-30-remove-demo-study-seed-implementation.md b/docs/plans/2026-03-30-remove-demo-study-seed-implementation.md
new file mode 100644
index 00000000..a4ccd499
--- /dev/null
+++ b/docs/plans/2026-03-30-remove-demo-study-seed-implementation.md
@@ -0,0 +1,48 @@
+# Remove Demo Study Seed Implementation Plan
+
+> **For Claude:** REQUIRED SUB-SKILL: Use superpowers:executing-plans to implement this plan task-by-task.
+
+**Goal:** Stop development initialization from auto-creating any demo study or fee data.
+
+**Architecture:** Remove the application startup hook that seeds demo fee data, while keeping schema setup and protected admin initialization intact. Add a regression test that proves the lifespan startup no longer calls the demo seed helper.
+
+**Tech Stack:** FastAPI, pytest, unittest.mock
+
+---
+
+### Task 1: Lock the startup behavior with a failing test
+
+**Files:**
+- Create: `backend/tests/test_app_startup.py`
+- Modify: `backend/app/main.py`
+
+**Step 1: Write the failing test**
+
+```python
+async def test_development_startup_does_not_seed_demo_fees():
+    ...
+```
+
+**Step 2: Run test to verify it fails**
+
+Run: `pytest backend/tests/test_app_startup.py -q`
+Expected: FAIL because startup still calls `seed_demo_fees`.
+
+**Step 3: Write minimal implementation**
+
+Remove the `seed_demo_fees` import and startup call from `backend/app/main.py`.
+
+**Step 4: Run test to verify it passes**
+
+Run: `pytest backend/tests/test_app_startup.py -q`
+Expected: PASS.
+
+### Task 2: Verify no regression in admin bootstrap
+
+**Files:**
+- Test: `backend/tests/test_protected_admin.py`
+
+**Step 1: Run targeted regression tests**
+
+Run: `pytest backend/tests/test_app_startup.py backend/tests/test_protected_admin.py -q`
+Expected: PASS.
diff --git a/frontend/src/components/Layout.vue b/frontend/src/components/Layout.vue
index f73115b5..4ba7d7d6 100644
--- a/frontend/src/components/Layout.vue
+++ b/frontend/src/components/Layout.vue
@@ -1,24 +1,26 @@
 <template>
   <el-container class="layout-container">
-    <el-aside :width="isCollapsed ? '68px' : '200px'" class="layout-aside" :class="{ collapsed: isCollapsed }" v-if="isAdmin || study.currentStudy">
+    <el-aside :width="isCollapsed ? '68px' : '200px'" class="layout-aside" :class="{ collapsed: isCollapsed }">
       <div class="aside-logo">
         <div class="logo-icon"></div>
         <span class="logo-text">{{ TEXT.common.appName }}</span>
       </div>
       <el-menu 
-        router 
         :default-active="activeMenu"
         :collapse="isCollapsed"
         :collapse-transition="true"
         class="aside-menu"
+        @select="handleMenuSelect"
       >
         <el-menu-item v-if="!isAdmin" index="/workbench">
           <el-icon><Monitor /></el-icon>
           <span>{{ TEXT.menu.workbench }}</span>
         </el-menu-item>
         
-        <template v-if="isAdmin">
-          <div class="menu-divider">{{ TEXT.menu.admin }}</div>
+        <el-menu-item-group v-if="isAdmin" class="menu-group">
+          <template #title>
+            <span class="menu-divider">{{ TEXT.menu.admin }}</span>
+          </template>
           <el-menu-item index="/admin/users">
             <el-icon><User /></el-icon>
             <span>{{ TEXT.menu.accountManagement }}</span>
@@ -31,10 +33,12 @@
             <el-icon><Document /></el-icon>
             <span>{{ TEXT.menu.auditLogs }}</span>
           </el-menu-item>
-        </template>
+        </el-menu-item-group>
         
-        <template v-if="study.currentStudy">
-          <div class="menu-divider">{{ TEXT.menu.currentProject }}</div>
+        <el-menu-item-group v-if="study.currentStudy" class="menu-group">
+          <template #title>
+            <span class="menu-divider">{{ TEXT.menu.currentProject }}</span>
+          </template>
           <el-menu-item index="/project/overview">
             <el-icon><House /></el-icon>
             <span>{{ TEXT.menu.projectOverview }}</span>
@@ -102,7 +106,7 @@
             <el-menu-item index="/knowledge/support-files">{{ TEXT.menu.knowledgeSupportFiles }}</el-menu-item>
             <el-menu-item index="/knowledge/instruction-files">{{ TEXT.menu.knowledgeInstructionFiles }}</el-menu-item>
           </el-sub-menu>
-        </template>
+        </el-menu-item-group>
       </el-menu>
     </el-aside>
 
@@ -194,11 +198,9 @@
       <el-main class="layout-main">
         <div class="content-wrapper">
           <router-view v-slot="{ Component }">
-            <transition name="fade-transform" mode="out-in">
-              <div :key="route.fullPath" class="ctms-route-shell">
-                <component :is="Component" :key="route.fullPath" />
-              </div>
-            </transition>
+            <div class="ctms-route-shell">
+              <component :is="Component" />
+            </div>
           </router-view>
         </div>
       </el-main>
@@ -392,6 +394,13 @@ const handleBreadcrumbCommand = (cmd: any) => {
   }
 };
 
+const handleMenuSelect = (index: string) => {
+  if (!index || index === route.path) {
+    return;
+  }
+  router.push(index);
+};
+
 watch(() => study.currentStudy, () => {
   loadSites();
 }, { immediate: true });
@@ -506,6 +515,7 @@ const onCommand = (cmd: string) => {
 }
 
 .menu-divider {
+  display: block;
   padding: 8px 14px 2px;
   font-size: 10px;
   font-weight: 700;
@@ -514,6 +524,10 @@ const onCommand = (cmd: string) => {
   letter-spacing: 1px;
 }
 
+.layout-aside :deep(.menu-group .el-menu-item-group__title) {
+  padding: 0 !important;
+}
+
 .layout-aside :deep(.el-menu-item) {
   height: 34px;
   line-height: 34px;
diff --git a/frontend/src/main.ts b/frontend/src/main.ts
index edb15326..30622e5c 100644
--- a/frontend/src/main.ts
+++ b/frontend/src/main.ts
@@ -15,12 +15,15 @@ import { useStudyStore } from "./store/study";
 const app = createApp(App);
 const pinia = createPinia();
 app.use(pinia);
-app.use(router);
 dayjs.locale("zh-cn");
 app.use(ElementPlus, { locale: zhCn });
 
 // 初始化项目上下文
 const studyStore = useStudyStore();
 studyStore.loadCurrentStudy();
+await studyStore.rehydrateStudyForLastUser();
+
+app.use(router);
+await router.isReady();
 
 app.mount("#app");
diff --git a/frontend/src/store/study.test.ts b/frontend/src/store/study.test.ts
new file mode 100644
index 00000000..fe26b971
--- /dev/null
+++ b/frontend/src/store/study.test.ts
@@ -0,0 +1,70 @@
+import { beforeEach, describe, expect, it, vi } from "vitest";
+import { createPinia, setActivePinia } from "pinia";
+
+const fetchStudies = vi.fn();
+
+vi.mock("../api/studies", () => ({
+  fetchStudies,
+}));
+
+type StorageLike = {
+  getItem: (key: string) => string | null;
+  setItem: (key: string, value: string) => void;
+  removeItem: (key: string) => void;
+  clear: () => void;
+};
+
+const createStorage = (): StorageLike => {
+  const data = new Map<string, string>();
+  return {
+    getItem: (key) => data.get(key) ?? null,
+    setItem: (key, value) => {
+      data.set(key, String(value));
+    },
+    removeItem: (key) => {
+      data.delete(key);
+    },
+    clear: () => {
+      data.clear();
+    },
+  };
+};
+
+describe("study store startup rehydration", () => {
+  beforeEach(() => {
+    setActivePinia(createPinia());
+    fetchStudies.mockReset();
+    Object.defineProperty(window, "localStorage", {
+      value: createStorage(),
+      configurable: true,
+    });
+  });
+
+  it("clears a stale persisted study when the backend no longer has any studies", async () => {
+    window.localStorage.setItem("ctms_last_login_email", "admin@example.com");
+    window.localStorage.setItem(
+      "ctms_current_study",
+      JSON.stringify({
+        id: "deleted-study",
+        code: "DEMO-CTMS",
+        name: "示例临床试验项目",
+      })
+    );
+    fetchStudies.mockResolvedValue({
+      data: {
+        items: [],
+      },
+    });
+
+    const { useStudyStore } = await import("./study");
+    const study = useStudyStore();
+    study.loadCurrentStudy();
+
+    expect(study.currentStudy?.id).toBe("deleted-study");
+
+    await study.rehydrateStudyForLastUser();
+
+    expect(study.currentStudy).toBeNull();
+    expect(window.localStorage.getItem("ctms_current_study")).toBeNull();
+  });
+});
diff --git a/frontend/src/store/study.ts b/frontend/src/store/study.ts
index c699a971..9bc975bc 100644
--- a/frontend/src/store/study.ts
+++ b/frontend/src/store/study.ts
@@ -77,6 +77,47 @@ export const useStudyStore = defineStore("study", () => {
     }
   };
 
+  const pickAvailableStudy = (
+    items: Study[],
+    userKey: string,
+    opts?: { preferActive?: boolean }
+  ): Study | null => {
+    if (!items.length) {
+      clearCurrentStudy();
+      return null;
+    }
+
+    if (currentStudy.value?.id) {
+      const matchedCurrent = items.find((item) => item.id === currentStudy.value?.id);
+      if (matchedCurrent) {
+        setCurrentStudy(matchedCurrent);
+        return matchedCurrent;
+      }
+    }
+
+    const normalized = normalizeUserKey(userKey || "");
+    const saved = normalized ? readLastStudyMap()[normalized] : null;
+    if (saved?.id) {
+      const matchedSaved = items.find((item) => item.id === saved.id);
+      if (matchedSaved) {
+        setCurrentStudy(matchedSaved);
+        return matchedSaved;
+      }
+    }
+
+    const fallback = opts?.preferActive
+      ? items.find((study) => study.status === "ACTIVE" && !study.is_locked) || items[0]
+      : items[0];
+
+    if (fallback) {
+      setCurrentStudy(fallback);
+      return fallback;
+    }
+
+    clearCurrentStudy();
+    return null;
+  };
+
   const ensureDefaultStudy = async () => {
     if (currentStudy.value) return currentStudy.value;
     try {
@@ -124,41 +165,25 @@ export const useStudyStore = defineStore("study", () => {
   };
 
   const restoreStudyForUser = async (userKey: string, opts?: { preferActive?: boolean }) => {
-    const normalized = normalizeUserKey(userKey || "");
-    if (!normalized) return null;
+    if (!normalizeUserKey(userKey || "")) return null;
     try {
       const { data } = await fetchStudies();
       const items = ((data as any).items || []) as Study[];
-      if (!items.length) {
-        clearCurrentStudy();
-        return null;
-      }
-
-      const saved = readLastStudyMap()[normalized];
-      if (saved?.id) {
-        const matched = items.find((item) => item.id === saved.id);
-        if (matched) {
-          setCurrentStudy(matched);
-          return matched;
-        }
-      }
-
-      const fallback = opts?.preferActive
-        ? items.find((study) => study.status === "ACTIVE" && !study.is_locked) || items[0]
-        : items[0];
-
-      if (fallback) {
-        setCurrentStudy(fallback);
-        return fallback;
-      }
-      clearCurrentStudy();
-      return null;
+      return pickAvailableStudy(items, userKey, opts);
     } catch {
       clearCurrentStudy();
       return null;
     }
   };
 
+  const rehydrateStudyForLastUser = async (opts?: { preferActive?: boolean }) => {
+    const userKey = localStorage.getItem("ctms_last_login_email") || "";
+    if (!normalizeUserKey(userKey)) {
+      return currentStudy.value;
+    }
+    return restoreStudyForUser(userKey, opts);
+  };
+
   const setCurrentStudyRole = (role: string | null) => {
     currentStudyRole.value = role;
     if (role) {
@@ -195,6 +220,7 @@ export const useStudyStore = defineStore("study", () => {
     ensureDefaultStudy,
     ensureDefaultActiveStudy,
     restoreStudyForUser,
+    rehydrateStudyForLastUser,
     clearCurrentStudy,
   };
 });
diff --git a/frontend/src/styles/main.css b/frontend/src/styles/main.css
index 442e784e..b73b0cc4 100644
--- a/frontend/src/styles/main.css
+++ b/frontend/src/styles/main.css
@@ -70,25 +70,6 @@
   --el-text-color-regular: var(--ctms-text-regular);
 }
 
-/* 现代滚动条 */
-::-webkit-scrollbar {
-  width: 6px;
-  height: 6px;
-}
-
-::-webkit-scrollbar-track {
-  background: transparent;
-}
-
-::-webkit-scrollbar-thumb {
-  background: #d9d9d9;
-  border-radius: 10px;
-}
-
-::-webkit-scrollbar-thumb:hover {
-  background: #bfbfbf;
-}
-
 /* 全局重置 */
 html,
 body,
@@ -430,23 +411,23 @@ body {
   margin-top: 0;
 }
 
-.ctms-descriptions :deep(.el-descriptions__label) {
+.ctms-descriptions .el-descriptions__label {
   font-weight: 500;
   color: var(--ctms-text-regular);
   background-color: #f8fafc;
 }
 
-.ctms-tabs :deep(.el-tabs__nav-wrap::after) {
+.ctms-tabs .el-tabs__nav-wrap::after {
   height: 1px;
   background-color: var(--ctms-border-color);
 }
 
-.ctms-tabs :deep(.el-tabs__item) {
+.ctms-tabs .el-tabs__item {
   font-weight: 500;
   color: var(--ctms-text-regular);
 }
 
-.ctms-tabs :deep(.el-tabs__item.is-active) {
+.ctms-tabs .el-tabs__item.is-active {
   color: var(--ctms-primary);
   font-weight: 600;
 }
@@ -538,4 +519,4 @@ body {
 /* ElMessageBox / ElDialog 遮罩层：左侧偏移侧边栏宽度，只覆盖主内容区域 */
 .el-overlay {
   left: var(--ctms-sidebar-width, 0px) !important;
-}
\ No newline at end of file
+}
diff --git a/frontend/src/views/admin/AuditLogs.vue b/frontend/src/views/admin/AuditLogs.vue
index 4b1aa49b..63bdf706 100644
--- a/frontend/src/views/admin/AuditLogs.vue
+++ b/frontend/src/views/admin/AuditLogs.vue
@@ -118,6 +118,7 @@
     </div>
 
     <el-drawer
+      v-if="detailVisible"
       v-model="detailVisible"
       direction="rtl"
       size="560px"
diff --git a/frontend/src/views/admin/ProjectDetail.vue b/frontend/src/views/admin/ProjectDetail.vue
index e9c16f73..85491aba 100644
--- a/frontend/src/views/admin/ProjectDetail.vue
+++ b/frontend/src/views/admin/ProjectDetail.vue
@@ -1390,7 +1390,7 @@
       </div>
       </div>
     </div>
-    <el-dialog append-to="body" v-model="publishConfirmVisible" title="发布确认" width="920px" top="8vh" class="setup-publish-dialog">
+    <el-dialog v-if="publishConfirmVisible" append-to="body" v-model="publishConfirmVisible" title="发布确认" width="920px" top="8vh" class="setup-publish-dialog">
       <div class="conflict-summary">
         <div>发布目标：立项配置草稿</div>
         <div>当前发布版本：{{ setupPublishedVersionText }}</div>
@@ -1451,6 +1451,7 @@
       </template>
     </el-dialog>
     <el-dialog
+      v-if="rollbackDialogVisible"
       append-to="body"
       v-model="rollbackDialogVisible"
       width="960px"
@@ -1499,7 +1500,7 @@
             :key="`head-${lane.branch}`"
             class="rollback-axis-lane-head-item"
             :class="{ 'is-main': lane.branch === 'main' }"
-            :style="{ left: `${lane.x}px` }"
+            :style="getRollbackAxisLeftStyle(lane.x)"
           >
             {{ formatAxisLaneLabel(lane.branch) }}
           </span>
@@ -1566,7 +1567,7 @@
                 v-for="lane in rollbackAxisLanes.filter(l => l.branch === 'main')"
                 :key="`${row.id}-${lane.branch}`"
                 class="rollback-axis-lane-segment is-main-lane"
-                :style="{ left: `${lane.x}px` }"
+                :style="getRollbackAxisLeftStyle(lane.x)"
               />
               <span
                 class="rollback-axis-dot"
@@ -1575,7 +1576,7 @@
                   'is-current': row.is_current_published,
                   'is-merge': row.mergeFromId !== null,
                 }"
-                :style="{ left: `${row.axisX}px` }"
+                :style="getRollbackAxisLeftStyle(row.axisX)"
               />
             </div>
             <div class="rollback-axis-content">
@@ -1661,6 +1662,7 @@
     </el-dialog>
 
     <el-drawer
+      v-if="projectMilestoneEditorVisible"
       v-model="projectMilestoneEditorVisible"
       direction="rtl"
       size="480px"
@@ -1763,6 +1765,7 @@
     </el-drawer>
 
     <el-drawer
+      v-if="siteMilestoneEditorVisible"
       v-model="siteMilestoneEditorVisible"
       direction="rtl"
       size="480px"
@@ -1842,6 +1845,7 @@
     </el-drawer>
 
     <el-drawer
+      v-if="siteEnrollmentEditorVisible"
       v-model="siteEnrollmentEditorVisible"
       direction="rtl"
       size="480px"
@@ -1911,6 +1915,7 @@
     </el-drawer>
 
     <el-drawer
+      v-if="monitoringStrategyEditorVisible"
       v-model="monitoringStrategyEditorVisible"
       direction="rtl"
       size="480px"
@@ -4772,6 +4777,9 @@ const getDisplayVersionLabel = (rawVersion: number): string => {
 
 const ROLLBACK_AXIS_LANE_GAP = 34;
 const ROLLBACK_AXIS_LANE_START = 18;
+const getRollbackAxisLeftStyle = (axisX?: number | null) => ({
+  left: `${Number.isFinite(axisX) ? axisX : ROLLBACK_AXIS_LANE_START}px`,
+});
 const normalizeAxisBranch = (branchName?: string | null): string => (branchName || "main").trim() || "main";
 const formatAxisLaneLabel = (branchName: string): string =>
   branchName === "main" ? "main" : branchName.replace(/^release\//, "");
@@ -6546,23 +6554,6 @@ onBeforeUnmount(() => {
   padding: 6px 0;
 }
 
-.rollback-axis-scroll::-webkit-scrollbar {
-  width: 5px;
-}
-
-.rollback-axis-scroll::-webkit-scrollbar-track {
-  background: transparent;
-}
-
-.rollback-axis-scroll::-webkit-scrollbar-thumb {
-  background: #c8d6e5;
-  border-radius: 10px;
-}
-
-.rollback-axis-scroll::-webkit-scrollbar-thumb:hover {
-  background: #a0b4cc;
-}
-
 /* SVG 覆盖层 */
 .rollback-axis-overlay {
   position: absolute;
diff --git a/frontend/src/views/admin/ProjectMembers.vue b/frontend/src/views/admin/ProjectMembers.vue
index 03d15ccc..f6621ef1 100644
--- a/frontend/src/views/admin/ProjectMembers.vue
+++ b/frontend/src/views/admin/ProjectMembers.vue
@@ -64,7 +64,7 @@
       </div>
     </div>
 
-    <el-dialog append-to=".layout-main .content-wrapper" :title="TEXT.modules.adminProjectMembers.newTitle" width="520px" v-model="addVisible" :close-on-click-modal="false">
+    <el-dialog v-if="addVisible" append-to=".layout-main .content-wrapper" :title="TEXT.modules.adminProjectMembers.newTitle" width="520px" v-model="addVisible" :close-on-click-modal="false">
       <el-form :model="newMember" label-width="120px" ref="addFormRef" :rules="addRules">
         <el-form-item :label="TEXT.modules.adminProjectMembers.user" prop="user_id">
           <el-select v-model="newMember.user_id" filterable :placeholder="TEXT.modules.adminProjectMembers.userPlaceholder">
diff --git a/frontend/src/views/admin/Projects.vue b/frontend/src/views/admin/Projects.vue
index 84960d04..5f4d5481 100644
--- a/frontend/src/views/admin/Projects.vue
+++ b/frontend/src/views/admin/Projects.vue
@@ -58,7 +58,7 @@
         </el-table>
       </div>
     </div>
-    <ProjectForm v-model:visible="formVisible" :project="editingProject" @saved="loadProjects" />
+    <ProjectForm v-if="formVisible" v-model:visible="formVisible" :project="editingProject" @saved="loadProjects" />
   </div>
 </template>
 
@@ -139,7 +139,11 @@ const handleDelete = async (study: Study) => {
       return;
     }
     
+    const isDeletingCurrentStudy = studyStore.currentStudy?.id === study.id;
     await deleteStudy(study.id);
+    if (isDeletingCurrentStudy) {
+      await studyStore.rehydrateStudyForLastUser({ preferActive: true });
+    }
     ElMessage.success("项目已删除");
     await loadProjects();
   } catch (err: any) {
diff --git a/frontend/src/views/admin/SiteCraBinding.vue b/frontend/src/views/admin/SiteCraBinding.vue
index 6dd7b9b9..3eb75b39 100644
--- a/frontend/src/views/admin/SiteCraBinding.vue
+++ b/frontend/src/views/admin/SiteCraBinding.vue
@@ -1,5 +1,5 @@
 <template>
-  <el-dialog append-to=".layout-main .content-wrapper" :title="TEXT.modules.adminSites.craBindTitle" width="520px" v-model="visibleProxy" :close-on-click-modal="false">
+  <el-dialog v-if="visibleProxy" append-to=".layout-main .content-wrapper" :title="TEXT.modules.adminSites.craBindTitle" width="520px" v-model="visibleProxy" :close-on-click-modal="false">
     <div class="tip">{{ TEXT.modules.adminSites.sitePrefix }}{{ site?.name }}</div>
     <el-form label-width="120px">
       <el-form-item :label="TEXT.modules.adminSites.craSelect">
diff --git a/frontend/src/views/admin/SiteForm.vue b/frontend/src/views/admin/SiteForm.vue
index 25257a2e..48e22c55 100644
--- a/frontend/src/views/admin/SiteForm.vue
+++ b/frontend/src/views/admin/SiteForm.vue
@@ -1,5 +1,5 @@
 <template>
-  <el-dialog append-to=".layout-main .content-wrapper" :title="site ? TEXT.modules.adminSites.editTitle : TEXT.modules.adminSites.newTitle" width="520px" v-model="visibleProxy" :close-on-click-modal="false">
+  <el-dialog v-if="visibleProxy" append-to=".layout-main .content-wrapper" :title="site ? TEXT.modules.adminSites.editTitle : TEXT.modules.adminSites.newTitle" width="520px" v-model="visibleProxy" :close-on-click-modal="false">
     <el-form ref="formRef" :model="form" :rules="rules" label-width="120px">
       <el-form-item :label="TEXT.common.fields.siteName" prop="name">
         <el-input v-model="form.name" :placeholder="TEXT.common.placeholders.input + TEXT.common.fields.siteName" />
diff --git a/frontend/src/views/admin/Sites.vue b/frontend/src/views/admin/Sites.vue
index 95db8604..36091f5b 100644
--- a/frontend/src/views/admin/Sites.vue
+++ b/frontend/src/views/admin/Sites.vue
@@ -63,7 +63,7 @@
       </div>
     </div>
     <SiteForm
-      v-if="projectId"
+      v-if="projectId && formVisible"
       v-model:visible="formVisible"
       :study-id="projectId"
       :site="editingSite"
diff --git a/frontend/src/views/admin/Users.vue b/frontend/src/views/admin/Users.vue
index 81179345..6b85373f 100644
--- a/frontend/src/views/admin/Users.vue
+++ b/frontend/src/views/admin/Users.vue
@@ -85,8 +85,8 @@
         </div>
       </div>
     </div>
-    <UserForm v-model:visible="formVisible" :user="editingUser" :admin-count="activeAdminCount" @saved="loadUsers" />
-    <UserResetPassword v-model:visible="resetVisible" :user="resetUser" @reset="loadUsers" />
+    <UserForm v-if="formVisible" v-model:visible="formVisible" :user="editingUser" :admin-count="activeAdminCount" @saved="loadUsers" />
+    <UserResetPassword v-if="resetVisible" v-model:visible="resetVisible" :user="resetUser" @reset="loadUsers" />
   </div>
 </template>
 
diff --git a/frontend/src/views/ia/MaterialEquipment.vue b/frontend/src/views/ia/MaterialEquipment.vue
index fd5fd5f8..455e5d84 100644
--- a/frontend/src/views/ia/MaterialEquipment.vue
+++ b/frontend/src/views/ia/MaterialEquipment.vue
@@ -39,6 +39,7 @@
     <StateEmpty v-else :description="TEXT.common.empty.selectProject" />
 
     <el-drawer
+      v-if="drawerVisible"
       v-model="drawerVisible"
       direction="rtl"
       size="620px"
diff --git a/frontend/src/views/ia/ProjectMilestones.vue b/frontend/src/views/ia/ProjectMilestones.vue
index 5aed53b2..149c6915 100644
--- a/frontend/src/views/ia/ProjectMilestones.vue
+++ b/frontend/src/views/ia/ProjectMilestones.vue
@@ -118,6 +118,7 @@
     <StateEmpty v-else :description="TEXT.common.empty.selectProject" />
 
     <el-drawer
+      v-if="editorVisible"
       v-model="editorVisible"
       direction="rtl"
       size="460px"
diff --git a/frontend/src/views/ia/RiskIssueMonitoringVisits.vue b/frontend/src/views/ia/RiskIssueMonitoringVisits.vue
index 232758f9..35f1a88f 100644
--- a/frontend/src/views/ia/RiskIssueMonitoringVisits.vue
+++ b/frontend/src/views/ia/RiskIssueMonitoringVisits.vue
@@ -116,6 +116,7 @@
       </div>
 
       <el-drawer
+        v-if="formDialogVisible"
         v-model="formDialogVisible"
         direction="rtl"
         size="580px"
@@ -289,7 +290,7 @@
         </template>
       </el-drawer>
 
-      <el-dialog v-model="viewDialogVisible" title="监查访视问题详情" width="680px">
+      <el-dialog v-if="viewDialogVisible" v-model="viewDialogVisible" title="监查访视问题详情" width="680px">
         <el-descriptions :column="2" border>
           <el-descriptions-item label="问题编号">{{ viewIssue?.issue_no || TEXT.common.fallback }}</el-descriptions-item>
           <el-descriptions-item label="问题来源">{{ viewIssue?.source || TEXT.common.fallback }}</el-descriptions-item>
diff --git a/frontend/src/views/overlayMounting.test.ts b/frontend/src/views/overlayMounting.test.ts
new file mode 100644
index 00000000..449896ea
--- /dev/null
+++ b/frontend/src/views/overlayMounting.test.ts
@@ -0,0 +1,80 @@
+import { describe, expect, it } from "vitest";
+import { readFileSync } from "node:fs";
+import { resolve } from "node:path";
+
+const readView = (relativePath: string) =>
+  readFileSync(resolve(__dirname, relativePath), "utf8");
+
+const normalizeWhitespace = (source: string) => source.replace(/\s+/g, " ").trim();
+
+describe("route view overlays are mounted only when visible", () => {
+  it("gates high-risk admin and subject overlays behind visible flags", () => {
+    const checks = [
+      {
+        file: "./admin/ProjectMembers.vue",
+        snippets: ['<el-dialog v-if="addVisible"', 'v-model="addVisible"'],
+      },
+      {
+        file: "./admin/Sites.vue",
+        snippets: ['<SiteForm', 'v-if="projectId && formVisible"'],
+      },
+      {
+        file: "./admin/SiteForm.vue",
+        snippets: ['<el-dialog v-if="visibleProxy"', 'v-model="visibleProxy"'],
+      },
+      {
+        file: "./admin/SiteCraBinding.vue",
+        snippets: ['<el-dialog v-if="visibleProxy"', 'v-model="visibleProxy"'],
+      },
+      {
+        file: "./subjects/SubjectDetail.vue",
+        snippets: [
+          '<el-dialog v-if="historyDialogVisible"',
+          '<el-dialog v-if="visitDialogVisible"',
+          '<el-dialog v-if="aeDialogVisible"',
+          '<el-dialog v-if="pdDialogVisible"',
+        ],
+      },
+      {
+        file: "./ia/ProjectMilestones.vue",
+        snippets: ['<el-drawer v-if="editorVisible"', 'v-model="editorVisible"'],
+      },
+      {
+        file: "./ia/MaterialEquipment.vue",
+        snippets: ['<el-drawer v-if="drawerVisible"', 'v-model="drawerVisible"'],
+      },
+      {
+        file: "./ia/RiskIssueMonitoringVisits.vue",
+        snippets: [
+          '<el-drawer v-if="formDialogVisible"',
+          'v-model="formDialogVisible"',
+          '<el-dialog v-if="viewDialogVisible"',
+          'v-model="viewDialogVisible"',
+        ],
+      },
+      {
+        file: "./admin/ProjectDetail.vue",
+        snippets: [
+          '<el-dialog v-if="publishConfirmVisible"',
+          'v-model="publishConfirmVisible"',
+          'v-if="rollbackDialogVisible"',
+          'v-model="rollbackDialogVisible"',
+          '<el-drawer v-if="projectMilestoneEditorVisible"',
+          '<el-drawer v-if="siteMilestoneEditorVisible"',
+          '<el-drawer v-if="siteEnrollmentEditorVisible"',
+          '<el-drawer v-if="monitoringStrategyEditorVisible"',
+          'const getRollbackAxisLeftStyle = (axisX?: number | null) => ({',
+          ':style="getRollbackAxisLeftStyle(lane.x)"',
+          ':style="getRollbackAxisLeftStyle(row.axisX)"',
+        ],
+      },
+    ];
+
+    for (const check of checks) {
+      const source = normalizeWhitespace(readView(check.file));
+      for (const snippet of check.snippets) {
+        expect(source, `${check.file} should include ${snippet}`).toContain(normalizeWhitespace(snippet));
+      }
+    }
+  });
+});
diff --git a/frontend/src/views/subjects/SubjectDetail.vue b/frontend/src/views/subjects/SubjectDetail.vue
index 36862a54..d73acea9 100644
--- a/frontend/src/views/subjects/SubjectDetail.vue
+++ b/frontend/src/views/subjects/SubjectDetail.vue
@@ -298,7 +298,7 @@
       </el-tabs>
     </el-card>
 
-    <el-dialog append-to=".layout-main .content-wrapper" v-model="historyDialogVisible" :title="TEXT.modules.subjectDetail.dialogHistory" width="520px">
+    <el-dialog v-if="historyDialogVisible" append-to=".layout-main .content-wrapper" v-model="historyDialogVisible" :title="TEXT.modules.subjectDetail.dialogHistory" width="520px">
       <el-form :model="historyForm" label-width="90px">
         <el-form-item :label="TEXT.common.fields.recordDate">
           <el-date-picker v-model="historyForm.record_date" type="date" value-format="YYYY-MM-DD" />
@@ -313,7 +313,7 @@
       </template>
     </el-dialog>
 
-    <el-dialog append-to=".layout-main .content-wrapper" v-model="visitDialogVisible" :title="TEXT.modules.subjectDetail.dialogVisit" width="560px">
+    <el-dialog v-if="visitDialogVisible" append-to=".layout-main .content-wrapper" v-model="visitDialogVisible" :title="TEXT.modules.subjectDetail.dialogVisit" width="560px">
       <el-form :model="visitForm" label-width="100px">
         <template v-if="!visitEditingId">
           <el-form-item :label="TEXT.common.fields.visitCode" required>
@@ -344,7 +344,7 @@
       </template>
     </el-dialog>
 
-    <el-dialog append-to=".layout-main .content-wrapper" v-model="aeDialogVisible" :title="TEXT.modules.subjectDetail.dialogAe" width="560px">
+    <el-dialog v-if="aeDialogVisible" append-to=".layout-main .content-wrapper" v-model="aeDialogVisible" :title="TEXT.modules.subjectDetail.dialogAe" width="560px">
       <el-form :model="aeForm" label-width="100px">
         <el-form-item :label="TEXT.common.fields.title" required>
           <el-input v-model="aeForm.term" />
@@ -383,7 +383,7 @@
       </template>
     </el-dialog>
 
-    <el-dialog append-to=".layout-main .content-wrapper" v-model="pdDialogVisible" :title="TEXT.modules.subjectDetail.dialogPd" width="560px">
+    <el-dialog v-if="pdDialogVisible" append-to=".layout-main .content-wrapper" v-model="pdDialogVisible" :title="TEXT.modules.subjectDetail.dialogPd" width="560px">
       <el-form :model="pdForm" label-width="100px">
         <el-form-item :label="TEXT.common.fields.pdNo">
           <el-input v-model="pdForm.pd_no" disabled :placeholder="TEXT.modules.subjectDetail.pdNoAuto" />
diff --git a/frontend/vite.config.ts b/frontend/vite.config.ts
index 44bdf546..34916c6f 100644
--- a/frontend/vite.config.ts
+++ b/frontend/vite.config.ts
@@ -2,7 +2,24 @@ import { defineConfig } from "vite";
 import vue from "@vitejs/plugin-vue";
 
 export default defineConfig({
-  plugins: [vue()],
+  plugins: [
+    vue(),
+    {
+      name: "sanitize-legacy-css",
+      generateBundle(_, bundle) {
+        for (const asset of Object.values(bundle)) {
+          if (asset.type !== "asset" || !asset.fileName.endsWith(".css") || typeof asset.source !== "string") {
+            continue;
+          }
+          asset.source = asset.source
+            .replace(/\.el-button::\-moz-focus-inner\{border:0\}/g, "")
+            .replace(/\.el-input__inner\[type=password\]::\-ms-reveal\{display:none\}/g, "")
+            .replace(/filter:alpha\(opacity=0\);/g, "")
+            .replace(/[^{}]*::\-webkit-scrollbar[^{}]*\{[^{}]*\}/g, "");
+        }
+      },
+    },
+  ],
   server: {
     host: true,
     port: 5173,