diff --git a/components/Button.tsx b/components/Button.tsx
new file mode 100644
index 0000000..26d601f
--- /dev/null
+++ b/components/Button.tsx
@@ -0,0 +1,32 @@
+import { Button as MuiButton, ButtonProps as MuiButtonProps } from '@mui/material';
+
+export type ButtonProps = MuiButtonProps;
+
+export function Button({ sx = [], ...props }: ButtonProps) {
+  return (
+    <MuiButton
+      disableElevation
+      disableRipple
+      {...props}
+      sx={[
+        {
+          py: 1.6,
+          borderRadius: 4,
+          fontSize: '1rem',
+          fontWeight: 600,
+          textTransform: 'none',
+          transition: 'all 0.2s cubic-bezier(0.4, 0, 0.2, 1)',
+          '&:hover': {
+            transform: 'translateY(-1px)',
+          },
+          '&:active': {
+            transform: 'translateY(0)',
+          },
+        },
+        ...(Array.isArray(sx) ? sx : [sx]),
+      ]}
+    />
+  );
+}
+
+export default Button;
diff --git a/components/StorageCleanerConfirm.tsx b/components/StorageCleanerConfirm.tsx
new file mode 100644
index 0000000..14da382
--- /dev/null
+++ b/components/StorageCleanerConfirm.tsx
@@ -0,0 +1,82 @@
+import {
+  Dialog,
+  DialogTitle,
+  DialogContent,
+  DialogActions,
+  Typography,
+  Box,
+} from '@mui/material';
+import type { StorageCleanerOptions } from '@/types/storage';
+import Button from '@/components/Button';
+
+export interface StorageCleanerConfirmProps {
+  open: boolean;
+  onClose: () => void;
+  onConfirm: () => void;
+  options: StorageCleanerOptions;
+}
+
+export function StorageCleanerConfirm({
+  open,
+  onClose,
+  onConfirm,
+  options,
+}: StorageCleanerConfirmProps) {
+  return (
+    <Dialog
+      open={open}
+      onClose={onClose}
+      fullWidth
+      maxWidth="xs"
+      slotProps={{
+        paper: {
+          sx: {
+            borderRadius: 4,
+            backgroundImage: 'none',
+            boxShadow: '0 8px 32px rgba(0,0,0,0.1)',
+          },
+        },
+      }}
+    >
+      <DialogTitle sx={{ textAlign: 'center', pb: 1, pt: 3, fontWeight: 700 }}>
+        确认清理
+      </DialogTitle>
+      <DialogContent sx={{ textAlign: 'center', pb: 2 }}>
+        <Typography variant="body2" color="text.secondary" sx={{ mb: 2 }}>
+          将清理以下存储类型：
+        </Typography>
+        <Box
+          sx={{
+            bgcolor: 'grey.50',
+            borderRadius: 3,
+            p: 2,
+            mb: 2,
+            display: 'inline-block',
+            textAlign: 'left',
+            minWidth: '60%',
+          }}
+        >
+          {options.localStorage && <Typography variant="body2">- localStorage</Typography>}
+          {options.sessionStorage && <Typography variant="body2">- sessionStorage</Typography>}
+          {options.indexedDB && <Typography variant="body2">- IndexedDB</Typography>}
+          {options.cookies && <Typography variant="body2">- Cookies</Typography>}
+          {options.cacheStorage && <Typography variant="body2">- Cache Storage</Typography>}
+          {options.serviceWorkers && <Typography variant="body2">- Service Workers</Typography>}
+        </Box>
+        <Typography variant="body2" color="text.secondary">
+          此操作不可撤销。
+        </Typography>
+      </DialogContent>
+      <DialogActions sx={{ p: 3, pt: 1, gap: 1 }}>
+        <Button variant="outlined" onClick={onClose} fullWidth>
+          取消
+        </Button>
+        <Button variant="contained" color="error" onClick={onConfirm} fullWidth>
+          确认清理
+        </Button>
+      </DialogActions>
+    </Dialog>
+  );
+}
+
+export default StorageCleanerConfirm;
diff --git a/docs/superpowers/plans/2026-04-05-popup-layout-fix-plan.md b/docs/superpowers/plans/2026-04-05-popup-layout-fix-plan.md
new file mode 100644
index 0000000..a070d99
--- /dev/null
+++ b/docs/superpowers/plans/2026-04-05-popup-layout-fix-plan.md
@@ -0,0 +1,32 @@
+# 实施计划：修复 Popup 布局与滚动条样式
+
+## 1. 目标
+
+按照设计规范实施固定高度布局与极简滚动条，确保扩展弹窗显示稳定且美观。
+
+## 2. 实施步骤
+
+### 2.1 CSS 核心样式更新 (`entrypoints/popup/App.css`)
+
+1. **视口锁定**: 更新 `html`, `body` 样式，固定 `width: 400px`, `height: 600px`。
+2. **根容器改造**:
+   - 将 `.app` 修改为 Flex 容器：`display: flex; flex-direction: column; height: 100%; overflow: hidden;`。
+   - 移除 `margin: 0 auto;` 和 `min-height: 100%;`。
+3. **滚动条变量与全局注入**:
+   - 在 `:root` 中定义 `--sb-` 开头的滚动条样式变量。
+   - 使用 `*::-webkit-scrollbar` 系列伪元素定义全局极简滚动条。
+
+### 2.2 React 结构重构 (`entrypoints/popup/App.tsx`)
+
+1. **注入滚动容器**: 在 `nav-container` 之后，将所有的页面渲染（`TimestampPage`, `StorageCleanerPage`）包裹在一个统一的 `Box` 中。
+2. **设置容器样式**: 给该 `Box` 设置 `sx={{ flex: 1, overflowY: 'auto', scrollbarGutter: 'stable' }}`。
+
+### 2.3 质量保障
+
+1. **Lint 检测**: 运行 `npm run lint` 检查样式变量引用和 JSX 结构。
+2. **类型检查**: 运行 `npm run compile` 验证 MUI 组件属性。
+
+## 3. 验证计划
+
+- 手动切换导航栏，观察窗口尺寸是否维持在 600px。
+- 在“存储清理”页面展开所有选项，观察右侧是否出现极细滚动条，且不会挤压内容。
diff --git a/docs/superpowers/specs/2026-04-05-popup-layout-fix-design.md b/docs/superpowers/specs/2026-04-05-popup-layout-fix-design.md
new file mode 100644
index 0000000..bdadb8b
--- /dev/null
+++ b/docs/superpowers/specs/2026-04-05-popup-layout-fix-design.md
@@ -0,0 +1,48 @@
+# 设计规范：Popup 弹窗固定高度与极简滚动条
+
+## 1. 目标
+
+解决 Chrome 扩展弹窗高度“只增不减”的布局问题，提供稳定的 600px 固定高度体验，并实现符合极简主义设计规范的可复用滚动条样式。
+
+## 2. 核心架构方案 (方案 A)
+
+采用 **Flex 布局 + 视口锁定** 的策略，将弹窗尺寸固定在 `400px * 600px`。
+
+### 2.1 容器层级设计
+
+- **`html`, `body`**: 锁定为 `400px * 600px`，并设置 `overflow: hidden` 防止出现双滚动条。
+- **`.app` (根容器)**:
+  - 设置为 `display: flex; flex-direction: column;`。
+  - 高度撑满父级 (`100%`)。
+  - 锁定 `overflow: hidden`。
+- **`nav-container` (导航栏)**:
+  - 位于顶部，高度固定，不参与 Flex 缩放。
+- **内容展示区 (Page Container)**:
+  - 设置 `flex: 1`，自动填充剩余空间。
+  - 设置 `overflow-y: auto`，启用局部滚动。
+  - 设置 `scrollbar-gutter: stable`，预留滚动条空间，防止布局抖动。
+
+## 3. 极简滚动条设计规范
+
+为了确保在所有页面和组件中表现一致，采用全局 Webkit 伪元素定制方案。
+
+### 3.1 变量定义
+
+在 `:root` 中定义 CSS 变量以增强兼容性和可维护性：
+
+- `--sb-width`: `6px` (极细)
+- `--sb-thumb-color`: `rgba(0, 0, 0, 0.1)` (浅灰色半透明)
+- `--sb-thumb-hover`: `rgba(0, 0, 0, 0.18)` (悬停时微深)
+- `--sb-track-color`: `transparent` (背景完全透明)
+
+### 3.2 样式表现
+
+- **滑块 (Thumb)**: 胶囊状圆角 (`10px`)。
+- **背景剪裁 (Background Clip)**: 使用 `content-box` 结合透明边框来实现滑块与边缘的微距感。
+- **自动应用**: 使用通配符 `*::-webkit-scrollbar` 确保全局所有溢出容器均自动继承此样式。
+
+## 4. 成功准则
+
+- 切换“时间戳”和“存储清理”页面时，浏览器窗口大小保持 `600px` 不变。
+- 当页面内容超过视口时，右侧显示细长、半透明的滚动条。
+- 内容加载或 Accordion 展开时，页面水平方向不发生位移。
diff --git a/entrypoints/popup/App.css b/entrypoints/popup/App.css
index 085ebb5..1390b0e 100644
--- a/entrypoints/popup/App.css
+++ b/entrypoints/popup/App.css
@@ -1,18 +1,4 @@
-/* 隐藏页面滚动条 */
-html,
-body {
-  margin: 0;
-  padding: 0;
-  width: 100%;
-  height: 100%;
-  scrollbar-gutter: stable;
-}
-
-/* 隐藏body滚动条但允许滚动 */
-body {
-  overflow: auto;
-}
-
+/* 极简滚动条变量 */
 :root {
   /* 统一圆角变量 */
   --radius: 8px;
@@ -25,16 +11,54 @@ body {
   /* 统一按钮文字颜色变量 */
   --btn-text: #333333;
   --border: 1px solid #e0e0e0;
+
+  /* 滚动条变量 */
+  --sb-width: 6px;
+  --sb-thumb-color: rgba(0, 0, 0, 0.1);
+  --sb-thumb-hover: rgba(0, 0, 0, 0.2);
+  --sb-track-color: transparent;
+}
+
+/* 强制固定视口尺寸 */
+html,
+body,
+#root {
+  margin: 0;
+  padding: 0;
+  width: 400px;
+  height: 600px;
+  overflow: hidden; /* 禁用外层滚动 */
+}
+
+/* 全局极简滚动条定制 */
+*::-webkit-scrollbar {
+  width: var(--sb-width);
+}
+
+*::-webkit-scrollbar-track {
+  background: var(--sb-track-color);
+}
+
+*::-webkit-scrollbar-thumb {
+  background: var(--sb-thumb-color);
+  border-radius: 10px;
+  background-clip: content-box;
+  border: 1px solid transparent;
+}
+
+*::-webkit-scrollbar-thumb:hover {
+  background: var(--sb-thumb-hover);
 }
 
 .app {
-  width: 400px;
-  min-height: 100%;
-  margin: 0 auto;
+  display: flex;
+  flex-direction: column;
+  width: 100%;
+  height: 100%;
   box-sizing: border-box;
   font-family:
     -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
-  overflow-x: hidden;
+  overflow: hidden; /* 内部由 flex 子项控制滚动 */
 }
 
 @keyframes fadeIn {
@@ -52,9 +76,12 @@ body {
 .nav-container {
   display: flex;
   justify-content: center;
-  margin-top: 16px;
-  margin-bottom: 16px;
+  padding-top: 16px;
+  padding-bottom: 16px;
   gap: 8px;
+  flex-shrink: 0; /* 禁止导航栏被挤压缩放 */
+  background-color: #fff;
+  border-bottom: 1px solid rgba(0, 0, 0, 0.05);
 }
 
 /* 导航按钮 */
diff --git a/entrypoints/popup/App.tsx b/entrypoints/popup/App.tsx
index 3050ccb..c208d03 100644
--- a/entrypoints/popup/App.tsx
+++ b/entrypoints/popup/App.tsx
@@ -93,8 +93,20 @@ function App() {
           </button>
         </Box>
       </Box>
-      {currentPage === 'timestamp' && <TimestampPage />}
-      {currentPage === 'storageCleaner' && <StorageCleanerPage />}
+      
+      {/* 统一滚动容器 */}
+      <Box 
+        sx={{ 
+          flex: 1, 
+          overflowY: 'auto', 
+          scrollbarGutter: 'stable',
+          display: 'flex',
+          flexDirection: 'column'
+        }}
+      >
+        {currentPage === 'timestamp' && <TimestampPage />}
+        {currentPage === 'storageCleaner' && <StorageCleanerPage />}
+      </Box>
     </div>
   );
 }
diff --git a/entrypoints/popup/pages/StorageCleanerPage.tsx b/entrypoints/popup/pages/StorageCleanerPage.tsx
index 0c0a477..7e9a448 100644
--- a/entrypoints/popup/pages/StorageCleanerPage.tsx
+++ b/entrypoints/popup/pages/StorageCleanerPage.tsx
@@ -4,7 +4,6 @@ import {
   Typography,
   Box,
   Checkbox,
-  Button,
   FormControlLabel,
   Alert,
   Snackbar,
@@ -16,8 +15,14 @@ import {
 import RefreshIcon from '@mui/icons-material/Refresh';
 import WarningIcon from '@mui/icons-material/Warning';
 import ExpandMoreIcon from '@mui/icons-material/ExpandMore';
+import Button from '@/components/Button';
+import StorageCleanerConfirm from '@/components/StorageCleanerConfirm';
 import { storageUtil } from '@/utils/chromeStorage';
-import type { StorageCleanerOptions, CleaningResult, StorageCleanerPreferences } from 'types/storage';
+import type {
+  StorageCleanerOptions,
+  CleaningResult,
+  StorageCleanerPreferences,
+} from 'types/storage';
 import {
   getCurrentTab,
   isRestrictedUrl,
@@ -70,10 +75,7 @@ export default function StorageCleanerPage() {
       setDomain(new URL(tab.url).hostname);
 
       // Load user preferences
-      const prefs = await storageUtil.get(
-        'storageCleaner/preferences',
-        DEFAULT_PREFERENCES,
-      );
+      const prefs = await storageUtil.get('storageCleaner/preferences', DEFAULT_PREFERENCES);
       setAutoRefresh(prefs?.autoRefresh ?? DEFAULT_PREFERENCES.autoRefresh);
       setOptions(prefs?.selectedTypes ?? DEFAULT_PREFERENCES.selectedTypes);
     };
@@ -84,10 +86,7 @@ export default function StorageCleanerPage() {
   const handleAutoRefreshChange = useCallback(async (checked: boolean) => {
     setAutoRefresh(checked);
     // Save preference immediately
-    const prefs = await storageUtil.get(
-      'storageCleaner/preferences',
-      DEFAULT_PREFERENCES,
-    );
+    const prefs = await storageUtil.get('storageCleaner/preferences', DEFAULT_PREFERENCES);
     await storageUtil.set('storageCleaner/preferences', {
       ...(prefs || DEFAULT_PREFERENCES),
       autoRefresh: checked,
@@ -98,13 +97,12 @@ export default function StorageCleanerPage() {
     setOptions((prev) => {
       const newOptions = { ...prev, [key]: !prev[key] };
       // Save options immediately
-      storageUtil.get('storageCleaner/preferences', DEFAULT_PREFERENCES)
-        .then(prefs => {
-          storageUtil.set('storageCleaner/preferences', {
-            ...(prefs || DEFAULT_PREFERENCES),
-            selectedTypes: newOptions,
-          });
+      storageUtil.get('storageCleaner/preferences', DEFAULT_PREFERENCES).then((prefs) => {
+        storageUtil.set('storageCleaner/preferences', {
+          ...(prefs || DEFAULT_PREFERENCES),
+          selectedTypes: newOptions,
         });
+      });
       return newOptions;
     });
   }, []);
@@ -122,12 +120,9 @@ export default function StorageCleanerPage() {
       serviceWorkers: checked,
     };
     setOptions(newOptions);
-    
+
     // Save options immediately
-    const prefs = await storageUtil.get(
-      'storageCleaner/preferences',
-      DEFAULT_PREFERENCES,
-    );
+    const prefs = await storageUtil.get('storageCleaner/preferences', DEFAULT_PREFERENCES);
     await storageUtil.set('storageCleaner/preferences', {
       ...(prefs || DEFAULT_PREFERENCES),
       selectedTypes: newOptions,
@@ -193,9 +188,6 @@ export default function StorageCleanerPage() {
     <Paper sx={{ p: 2, m: 1, borderRadius: 2 }}>
       {/* Header */}
       <Box sx={{ textAlign: 'center', mb: 2 }}>
-        <Typography variant="h5" component="h1" sx={{ mb: 1 }}>
-          存储清理
-        </Typography>
         <Typography variant="body2" color="text.secondary">
           当前页面: {domain || '加载中...'}
         </Typography>
@@ -327,10 +319,8 @@ export default function StorageCleanerPage() {
           variant="contained"
           onClick={() => setShowConfirm(true)}
           sx={{
-            py: 1.6, borderRadius: 3, fontSize: '1rem', fontWeight: 600, textTransform: 'none',
-            bgcolor: 'primary.main', transition: 'all 0.2s',
-            '&:hover': { bgcolor: 'primary.dark', transform: 'translateY(-1px)' },
-            '&:active': { transform: 'translateY(0)' }
+            bgcolor: 'primary.main',
+            '&:hover': { bgcolor: 'primary.dark' },
           }}
           disabled={loading}
           fullWidth
@@ -362,60 +352,12 @@ export default function StorageCleanerPage() {
       )}
 
       {/* Confirmation Dialog */}
-      {showConfirm && (
-        <Paper
-          sx={{
-            position: 'absolute',
-            top: 0,
-            left: 0,
-            right: 0,
-            bottom: 0,
-            bgcolor: 'rgba(255,255,255, 0.95)',
-            display: 'flex',
-            flexDirection: 'column',
-            alignItems: 'center',
-            justifyContent: 'center',
-            gap: 2,
-            zIndex: 10,
-          }}
-        >
-          <Typography variant="h6">确认清理</Typography>
-          <Typography variant="body2" color="text.secondary" sx={{ textAlign: 'center', mb: 1 }}>
-            将清理以下存储类型：
-          </Typography>
-          <Box sx={{ mb: 1 }}>
-            {options.localStorage && (
-              <Typography variant="body2">- localStorage</Typography>
-            )}
-            {options.sessionStorage && (
-              <Typography variant="body2">- sessionStorage</Typography>
-            )}
-            {options.indexedDB && <Typography variant="body2">- IndexedDB</Typography>}
-            {options.cookies && <Typography variant="body2">- Cookies</Typography>}
-            {options.cacheStorage && (
-              <Typography variant="body2">- Cache Storage</Typography>
-            )}
-            {options.serviceWorkers && (
-              <Typography variant="body2">- Service Workers</Typography>
-            )}
-          </Box>
-          <Typography
-            variant="body2"
-            color="text.secondary"
-            sx={{ textAlign: 'center', mb: 1 }}
-          >
-            此操作不可撤销。
-          </Typography>
-          <Box sx={{ display: 'flex', gap: 1 }}>
-            <Button variant="outlined" onClick={() => setShowConfirm(false)}>
-              取消
-            </Button>
-            <Button variant="contained" color="error" onClick={handleClean}>
-              确认清理
-            </Button>
-          </Box>
-        </Paper>
-      )}
+      <StorageCleanerConfirm
+        open={showConfirm}
+        onClose={() => setShowConfirm(false)}
+        onConfirm={handleClean}
+        options={options}
+      />
 
       {/* Snackbar */}
       <Snackbar
diff --git a/entrypoints/popup/pages/TimestampPage.tsx b/entrypoints/popup/pages/TimestampPage.tsx
index a36ede5..a336786 100644
--- a/entrypoints/popup/pages/TimestampPage.tsx
+++ b/entrypoints/popup/pages/TimestampPage.tsx
@@ -1,7 +1,6 @@
 import React, { useState, useEffect, useCallback, useMemo } from 'react';
 import dayjs from '@/utils/dayjs';
 import {
-  Button,
   TextField,
   Select,
   MenuItem,
@@ -21,6 +20,7 @@ import ContentCopyIcon from '@mui/icons-material/ContentCopy';
 import SwapHorizIcon from '@mui/icons-material/SwapHoriz'; 
 import CheckIcon from '@mui/icons-material/Check';
 import AccessTimeIcon from '@mui/icons-material/AccessTime';
+import Button from '@/components/Button';
 
 // ================= 常量配置 =================
 const DATE_FORMAT = 'YYYY/MM/DD HH:mm:ss';
@@ -324,12 +324,6 @@ export default function TimestampPage() {
             <Button
               key={m} fullWidth disableRipple
               onClick={() => { setMode(m); setError(''); setResult(''); }}
-              sx={{
-                position: 'relative', zIndex: 1, borderRadius: 3, py: 1, textTransform: 'none',
-                fontSize: '0.875rem', fontWeight: 500, transition: 'color 0.2s',
-                color: mode === m ? 'text.primary' : 'text.disabled',
-                '&:hover': { bgcolor: 'transparent', color: mode === m ? 'text.primary' : 'text.secondary' },
-              }}
             >
               {m === 'ts2dt' ? '时间戳 → 日期' : '日期 → 时间戳'}
             </Button>
@@ -384,12 +378,6 @@ export default function TimestampPage() {
         <Button
           fullWidth variant="contained" disableElevation disableRipple
           onClick={convert}
-          sx={{
-            py: 1.6, borderRadius: 3, fontSize: '1rem', fontWeight: 600, textTransform: 'none',
-            bgcolor: 'primary.main', transition: 'all 0.2s',
-            '&:hover': { bgcolor: 'primary.dark', transform: 'translateY(-1px)' },
-            '&:active': { transform: 'translateY(0)' }
-          }}
         >
           立即转换
         </Button>