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+# App Detail Fixed Sidebar Scroll Implementation Plan
+
+> **For agentic workers:** REQUIRED SUB-SKILL: Use superpowers:subagent-driven-development (recommended) or superpowers:executing-plans to implement this plan task-by-task. Steps use checkbox (`- [ ]`) syntax for tracking.
+
+**Goal:** Keep the app detail modal's left action/meta column fixed on desktop while the right detail/review column scrolls independently.
+
+**Architecture:** Reuse the existing `AppDetailModal.vue` popup and change only its internal layout classes/markers. The modal panel becomes a bounded, non-scrolling shell on desktop, while the right column becomes the desktop scroll container; mobile keeps the single-column scroll behavior.
+
+**Tech Stack:** Vue 3 SFC, Tailwind CSS utilities, Vitest, Testing Library Vue.
+
+---
+
+## File Structure
+
+- Modify: `src/components/AppDetailModal.vue` - adjust modal shell, left column, right scroll column, and scroll reset target.
+- Modify: `src/__tests__/unit/AppDetailModal.test.ts` - assert modal shell and scroll column contract.
+
+## Task 1: Add Layout Contract Test
+
+**Files:**
+- Modify: `src/__tests__/unit/AppDetailModal.test.ts`
+
+- [ ] **Step 1: Add assertions to the popup modal test**
+
+In `src/__tests__/unit/AppDetailModal.test.ts`, update `renders detail content inside a popup-style modal overlay` so the body after the `.modal-panel` assertion is:
+
+```ts
+    const panel = overlay?.querySelector(".modal-panel");
+    expect(panel).toBeTruthy();
+    expect(panel?.className).toContain("overflow-hidden");
+    expect(panel?.className).toContain("lg:max-h-[85vh]");
+    expect(panel?.querySelector('[data-testid="detail-fixed-sidebar"]')).toBeTruthy();
+    expect(panel?.querySelector('[data-testid="detail-scroll-content"]')).toBeTruthy();
+    expect(
+      panel?.querySelector('[data-testid="detail-scroll-content"]')?.className,
+    ).toContain("lg:overflow-y-auto");
+```
+
+- [ ] **Step 2: Run test to verify failure**
+
+Run: `npm run test -- --run src/__tests__/unit/AppDetailModal.test.ts`
+
+Expected: FAIL because `data-testid="detail-fixed-sidebar"`, `data-testid="detail-scroll-content"`, and the new modal classes are not present.
+
+## Task 2: Implement Fixed Sidebar Layout
+
+**Files:**
+- Modify: `src/components/AppDetailModal.vue`
+- Modify: `src/__tests__/unit/AppDetailModal.test.ts`
+
+- [ ] **Step 1: Update modal shell classes**
+
+In `src/components/AppDetailModal.vue`, change the `.modal-panel` class from:
+
+```vue
+class="modal-panel relative w-full max-w-5xl max-h-[85vh] overflow-y-auto overscroll-contain scrollbar-nowidth rounded-3xl border border-white/10 bg-white/95 px-6 pb-6 shadow-2xl dark:border-slate-800 dark:bg-slate-900"
+```
+
+to:
+
+```vue
+class="modal-panel relative flex w-full max-w-5xl max-h-[85vh] overflow-y-auto overscroll-contain scrollbar-nowidth rounded-3xl border border-white/10 bg-white/95 px-6 pb-6 shadow-2xl dark:border-slate-800 dark:bg-slate-900 lg:max-h-[85vh] lg:overflow-hidden lg:pb-0"
+```
+
+- [ ] **Step 2: Move the return button into the fixed sidebar**
+
+In `src/components/AppDetailModal.vue`, replace the top-level return button and main layout start with:
+
+```vue
+        <!-- 主布局：左侧信息 + 右侧内容 -->
+        <div class="flex w-full flex-col gap-6 lg:min-h-0 lg:flex-row">
+          <!-- 左侧：图标、版本、来源、按钮、元信息 -->
+          <div
+            data-testid="detail-fixed-sidebar"
+            class="w-full flex-shrink-0 space-y-5 lg:w-72 lg:self-start lg:py-4"
+          >
+            <button
+              type="button"
+              class="inline-flex items-center gap-2 rounded-full border border-slate-200/70 bg-white/90 px-4 py-2 text-sm font-medium text-slate-600 shadow-lg backdrop-blur-sm transition hover:bg-slate-50 hover:text-slate-900 dark:border-slate-700 dark:bg-slate-800/90 dark:text-slate-400 dark:hover:bg-slate-700 dark:hover:text-slate-200"
+              @click="closeModal"
+              aria-label="返回"
+            >
+              <i class="fas fa-arrow-left"></i>
+              <span>返回</span>
+            </button>
+```
+
+Remove the old sticky top-level return button and the old left column opening:
+
+```vue
+        <!-- 返回按钮 - sticky定位在模态框内部左上角，滚动时始终可见 -->
+        <button ...>...</button>
+
+        <!-- 主布局：左侧信息 + 右侧内容 -->
+        <div class="flex flex-col lg:flex-row gap-6">
+          <!-- 左侧：图标、版本、来源、按钮、元信息 -->
+          <div class="w-full lg:w-72 flex-shrink-0 space-y-5">
+```
+
+- [ ] **Step 3: Make the right column the desktop scroll container**
+
+In `src/components/AppDetailModal.vue`, change the right column opening from:
+
+```vue
+          <div class="flex-1 min-w-0 space-y-5">
+```
+
+to:
+
+```vue
+          <div
+            data-testid="detail-scroll-content"
+            class="min-w-0 flex-1 space-y-5 lg:max-h-[85vh] lg:overflow-y-auto lg:overscroll-contain lg:py-4 lg:pr-2"
+          >
+```
+
+- [ ] **Step 4: Update scroll reset target if needed**
+
+In `src/App.vue`, keep the existing modal scroll reset selector if it still points at `.modal-panel`. If the right column needs reset instead, change the query to:
+
+```ts
+const modal = document.querySelector(
+  '[data-app-modal="detail"] [data-testid="detail-scroll-content"]',
+);
+```
+
+Use `modal.scrollTop = 0` as it does today.
+
+- [ ] **Step 5: Run focused test**
+
+Run: `npm run test -- --run src/__tests__/unit/AppDetailModal.test.ts`
+
+Expected: PASS.
+
+- [ ] **Step 6: Run build verification**
+
+Run: `npm run build:vite`
+
+Expected: PASS.
+
+- [ ] **Step 7: Commit implementation**
+
+Run:
+
+```bash
+git add src/components/AppDetailModal.vue src/App.vue src/__tests__/unit/AppDetailModal.test.ts
+git commit -m "fix(ui): pin detail modal sidebar"
+```
+
+Expected: commit succeeds.