diff --git a/src/components/CopyButton.tsx b/src/components/CopyButton.tsx
index 23f9bb3..6adf5c0 100644
--- a/src/components/CopyButton.tsx
+++ b/src/components/CopyButton.tsx
@@ -53,6 +53,7 @@ export const CopyButton: React.FC<CopyButtonProps> = ({
       type="button"
       onClick={handleCopy}
       title={tooltip ?? t('buttons.copy')}
+      aria-label={tooltip ?? t('buttons.copy')}
       className={cn(
         buttonVariants({ variant, size }),
         copied &&
@@ -62,7 +63,7 @@ export const CopyButton: React.FC<CopyButtonProps> = ({
       {...props}
     >
       {copied ? (
-        <Check className="h-[1.2em] w-[1.2em] animate-in fade-in zoom-in-75 duration-200" />
+        <Check className="h-[1.2em] w-[1.2em]" />
       ) : (
         <Copy className="h-[1.2em] w-[1.2em]" />
       )}
diff --git a/src/components/CopyButton/__tests__/index.test.tsx b/src/components/CopyButton/__tests__/index.test.tsx
new file mode 100644
index 0000000..64af285
--- /dev/null
+++ b/src/components/CopyButton/__tests__/index.test.tsx
@@ -0,0 +1,194 @@
+import { beforeEach, describe, expect, it, vi } from 'vitest';
+import { act, render, screen, waitFor } from '@testing-library/react';
+import userEvent from '@testing-library/user-event';
+
+// unmock the globally-mocked component so we test the real implementation
+vi.unmock('@/components/CopyButton');
+
+vi.mock('@/utils/clipboard', () => ({
+  copyTextToClipboard: vi.fn(),
+}));
+
+vi.mock('sonner', () => ({
+  toast: {
+    success: vi.fn(),
+    error: vi.fn(),
+  },
+}));
+
+import { CopyButton } from '@/components/CopyButton';
+import { copyTextToClipboard } from '@/utils/clipboard';
+import { toast } from 'sonner';
+
+const mockedCopy = vi.mocked(copyTextToClipboard);
+const mockedToast = vi.mocked(toast);
+
+describe('CopyButton', () => {
+  beforeEach(() => {
+    vi.useFakeTimers({ shouldAdvanceTime: true });
+    vi.clearAllMocks();
+  });
+
+  afterEach(() => {
+    vi.useRealTimers();
+  });
+
+  it('复制成功时调用 copyTextToClipboard 并传入正确 text', async () => {
+    mockedCopy.mockResolvedValue(true);
+    const user = userEvent.setup({ advanceTimers: vi.advanceTimersByTime });
+
+    render(<CopyButton text="hello world" />);
+
+    await user.click(screen.getByRole('button'));
+
+    expect(mockedCopy).toHaveBeenCalledWith('hello world');
+    expect(mockedToast.success).toHaveBeenCalled();
+  });
+
+  it('复制成功后图标切换为 Check，1.5 秒后恢复', async () => {
+    mockedCopy.mockResolvedValue(true);
+    const user = userEvent.setup({ advanceTimers: vi.advanceTimersByTime });
+
+    render(<CopyButton text="test" />);
+
+    // 点击后复制成功，按钮获得 emerald 样式（说明切到了 Check 状态）
+    await user.click(screen.getByRole('button'));
+
+    await waitFor(() => {
+      expect(screen.getByRole('button').className).toContain('text-emerald');
+    });
+
+    // 1.5 秒后样式恢复
+    act(() => {
+      vi.advanceTimersByTime(1500);
+    });
+
+    await waitFor(() => {
+      expect(screen.getByRole('button').className).not.toContain('text-emerald');
+    });
+  });
+
+  it('复制空文本时弹出 error toast', async () => {
+    const user = userEvent.setup({ advanceTimers: vi.advanceTimersByTime });
+
+    render(<CopyButton text="" />);
+
+    await user.click(screen.getByRole('button'));
+
+    expect(mockedCopy).not.toHaveBeenCalled();
+    expect(mockedToast.error).toHaveBeenCalled();
+  });
+
+  it('复制失败时弹出 error toast', async () => {
+    mockedCopy.mockResolvedValue(false);
+    const user = userEvent.setup({ advanceTimers: vi.advanceTimersByTime });
+
+    render(<CopyButton text="something" />);
+
+    await user.click(screen.getByRole('button'));
+
+    expect(mockedCopy).toHaveBeenCalledWith('something');
+    expect(mockedToast.error).toHaveBeenCalled();
+  });
+
+  // ==================== 新增测试 ====================
+
+  it('初始渲染时显示 Copy 图标且无 emerald 样式', () => {
+    render(<CopyButton text="initial" />);
+
+    const button = screen.getByRole('button');
+    expect(button.className).not.toContain('text-emerald');
+    // 通过 aria-label 确认按钮存在，图标由 lucide 渲染为 svg
+    expect(button).toHaveAttribute('aria-label');
+  });
+
+  it('自定义 tooltip 会覆盖默认 title 和 aria-label', () => {
+    render(<CopyButton text="tooltip-test" tooltip="自定义提示" />);
+
+    const button = screen.getByRole('button');
+    expect(button).toHaveAttribute('title', '自定义提示');
+    expect(button).toHaveAttribute('aria-label', '自定义提示');
+  });
+
+  it('className 被正确透传到按钮', () => {
+    render(<CopyButton text="class-test" className="my-custom-class" />);
+
+    const button = screen.getByRole('button');
+    expect(button.className).toContain('my-custom-class');
+  });
+
+  it('点击事件阻止冒泡', async () => {
+    mockedCopy.mockResolvedValue(true);
+    const user = userEvent.setup({ advanceTimers: vi.advanceTimersByTime });
+    const parentClick = vi.fn();
+
+    render(
+      <div onClick={parentClick}>
+        <CopyButton text="stop-propagation" />
+      </div>,
+    );
+
+    await user.click(screen.getByRole('button'));
+
+    expect(mockedCopy).toHaveBeenCalled();
+    expect(parentClick).not.toHaveBeenCalled();
+  });
+
+  it('组件卸载时清除定时器，不触发状态更新警告', async () => {
+    mockedCopy.mockResolvedValue(true);
+    const user = userEvent.setup({ advanceTimers: vi.advanceTimersByTime });
+
+    const { unmount } = render(<CopyButton text="unmount-test" />);
+
+    await user.click(screen.getByRole('button'));
+
+    // 在 1.5 秒超时到期前卸载组件
+    act(() => {
+      vi.advanceTimersByTime(500);
+    });
+
+    // 卸载不应抛出 "Can't perform a React state update on an unmounted component" 警告
+    expect(() => unmount()).not.toThrow();
+
+    // 前进剩余时间，确认没有异常
+    act(() => {
+      vi.advanceTimersByTime(2000);
+    });
+  });
+
+  it('快速连续点击不会创建多个重叠定时器', async () => {
+    mockedCopy.mockResolvedValue(true);
+    const user = userEvent.setup({ advanceTimers: vi.advanceTimersByTime });
+
+    render(<CopyButton text="rapid-click" />);
+
+    const button = screen.getByRole('button');
+
+    // 快速点击 3 次
+    await user.click(button);
+    await user.click(button);
+    await user.click(button);
+
+    // copyTextToClipboard 应该被调用 3 次（每次点击都执行）
+    expect(mockedCopy).toHaveBeenCalledTimes(3);
+
+    // 但 setTimeout 相关的 clearTimeout + setTimeout 组合应正常工作
+    //  advance 1.5 秒后，copied 状态应恢复为 false
+    act(() => {
+      vi.advanceTimersByTime(1500);
+    });
+
+    await waitFor(() => {
+      expect(button.className).not.toContain('text-emerald');
+    });
+  });
+
+  it('其他 button props 通过 ...props 透传', () => {
+    render(<CopyButton text="props-test" data-testid="copy-btn" disabled id="copy-button-id" />);
+
+    const button = screen.getByRole('button');
+    expect(button).toHaveAttribute('data-testid', 'copy-btn');
+    expect(button).toBeDisabled();
+    expect(button).toHaveAttribute('id', 'copy-button-id');
+  });
+});
diff --git a/src/pages/Base64Converter/Base64ConverterSection.tsx b/src/pages/Base64Converter/Base64ConverterSection.tsx
index ba4912c..469d949 100644
--- a/src/pages/Base64Converter/Base64ConverterSection.tsx
+++ b/src/pages/Base64Converter/Base64ConverterSection.tsx
@@ -1,7 +1,7 @@
 import { Image as ImageIcon, Trash2, Upload } from 'lucide-react';
 import TextInputArea from '@/components/TextInputArea';
 import { useI18n } from '@/utils/chromeI18n';
-import CopyButton from '@/components/CopyButton';
+import { CopyButton } from '@/components/CopyButton';
 import DecodeResultPaper from '@/components/DecodeResultPaper';
 import { Button } from '@/components/ui/button';
 import { downloadBlob, formatFileSize } from '@/utils/base64Converter';
diff --git a/src/pages/Base64Converter/TextMode.tsx b/src/pages/Base64Converter/TextMode.tsx
index 7517cc5..3392e44 100644
--- a/src/pages/Base64Converter/TextMode.tsx
+++ b/src/pages/Base64Converter/TextMode.tsx
@@ -1,7 +1,7 @@
 import { useCallback, useEffect, useMemo, useState } from 'react';
 import TextInputArea from '@/components/TextInputArea';
 import { useI18n } from '@/utils/chromeI18n';
-import CopyButton from '@/components/CopyButton';
+import { CopyButton } from '@/components/CopyButton';
 import { base64ToText, textToBase64 } from '@/utils/base64Converter';
 import SwitchButtonGroup from '@/components/SwitchButtonGroup';
 import { useContextMenuData } from '@/utils/useContextMenuData';
diff --git a/src/pages/JsonTools/JsonConvertSection.tsx b/src/pages/JsonTools/JsonConvertSection.tsx
index 31e38c6..4218aff 100644
--- a/src/pages/JsonTools/JsonConvertSection.tsx
+++ b/src/pages/JsonTools/JsonConvertSection.tsx
@@ -1,7 +1,7 @@
 import React, { useEffect, useMemo, useState } from 'react';
 import { useI18n } from '@/utils/chromeI18n';
 import { formatBytes } from '@/utils/format';
-import CopyButton from '@/components/CopyButton';
+import { CopyButton } from '@/components/CopyButton';
 import TextInputArea from '@/components/TextInputArea';
 import { validateJson } from '@/utils/jsonFormatter';
 import { cn } from '@/lib/utils';
diff --git a/src/pages/JsonTools/JsonFormatSection.tsx b/src/pages/JsonTools/JsonFormatSection.tsx
index d141ed6..116c06a 100644
--- a/src/pages/JsonTools/JsonFormatSection.tsx
+++ b/src/pages/JsonTools/JsonFormatSection.tsx
@@ -7,7 +7,7 @@ import {
   validateJson,
 } from '@/utils/jsonFormatter';
 import { formatBytes } from '@/utils/format';
-import CopyButton from '@/components/CopyButton';
+import { CopyButton } from '@/components/CopyButton';
 import SwitchButtonGroup from '@/components/SwitchButtonGroup';
 import TextInputArea from '@/components/TextInputArea';
 import { Checkbox } from '@/components/ui/checkbox';
diff --git a/src/pages/Jwt/JwtSection.tsx b/src/pages/Jwt/JwtSection.tsx
index 4a11e0f..7c77fe1 100644
--- a/src/pages/Jwt/JwtSection.tsx
+++ b/src/pages/Jwt/JwtSection.tsx
@@ -1,4 +1,4 @@
-import CopyButton from '@/components/CopyButton';
+import { CopyButton } from '@/components/CopyButton';
 import { useI18n } from '@/utils/chromeI18n';
 import { stringifyJson } from '@/utils/jwt';
 import { cn } from '@/lib/utils';
diff --git a/src/pages/Jwt/index.tsx b/src/pages/Jwt/index.tsx
index 07aa1cb..31a68e6 100644
--- a/src/pages/Jwt/index.tsx
+++ b/src/pages/Jwt/index.tsx
@@ -1,5 +1,5 @@
 import TextInputArea from '@/components/TextInputArea';
-import CopyButton from '@/components/CopyButton';
+import { CopyButton } from '@/components/CopyButton';
 import JwtSection from './JwtSection';
 import { useJwt } from './useJwt';
 import { useI18n } from '@/utils/chromeI18n';
diff --git a/src/pages/Timestamp/LiveClock.tsx b/src/pages/Timestamp/LiveClock.tsx
index a75b352..af10d18 100644
--- a/src/pages/Timestamp/LiveClock.tsx
+++ b/src/pages/Timestamp/LiveClock.tsx
@@ -1,7 +1,7 @@
 import React, { useEffect, useState } from 'react';
 import { Clock } from 'lucide-react';
 import { toast } from 'sonner';
-import CopyButton from '@/components/CopyButton';
+import { CopyButton } from '@/components/CopyButton';
 import type { UnitType } from './constants';
 import { msToUnit } from './constants';
 import { useI18n } from '@/utils/chromeI18n';
diff --git a/src/pages/Timestamp/ResultView.tsx b/src/pages/Timestamp/ResultView.tsx
index 076d01e..b4a586c 100644
--- a/src/pages/Timestamp/ResultView.tsx
+++ b/src/pages/Timestamp/ResultView.tsx
@@ -1,5 +1,5 @@
 import React from 'react';
-import CopyButton from '@/components/CopyButton';
+import { CopyButton } from '@/components/CopyButton';
 import { useI18n } from '@/utils/chromeI18n';
 import { cn } from '@/lib/utils';