升级TailwindCSS v3至v4后出现"Unknown word 'use strict'"错误求助

在Vite React应用中，原本使用Tailwind 3.4.17，执行npx @tailwindcss/upgrade升级到v4后，启动Vite服务器时出现如下错误：

10:15:37OM modern 费assets模拟班行 water_偶像 1999
10:15:37 PM [vite] Internal server error: [postcss] postcss-import: /Users/oliver/Documents/code/news-planner/client/node_modules/tailwindcss/lib/index.js:1:1: Unknown word "use strict"
  Plugin: vite:css
  File: /Users/oliver/Documents/code/news-planner/client/node_modules/tailwindcss/lib/index.js:1:0
  1  |  "use strict";
     |  ^
  2  |  module.exports = require("./plugin");
  3  |  
      at Input.error (/Users/oliver/Documents/code/news-planner/client/node_modules/postcss/lib/input.js:113:16)
      at Parser.unknownWord (/Users/oliver/Documents/code/news-planner/client/node_modules/postcss/lib/parser.js:595:22)
      at Parser.other (/Users/oliver/Documents/code/news-planner/client/node_modules/postcss/lib/parser.js:437:12)
      at Parser.parse (/Users/oliver/Documents/code/news-planner/client/node_modules/postcss/lib/parser.js:472:16)
      at parse (/Users/oliver/Documents/code/news-planner/client/node_modules/postcss/lib/parse.js:11:12)
      at get root [as root] (/Users/oliver/Documents/code/news-planner/client/node_modules/postcss/lib/no-work-result.js:43:14)
      at Result.get [as root] (/Users/oliver/Documents/code/news-planner/client/node_modules/postcss/lib/no-work-result.js:77:21)
      at loadImportContent (file:///Users/oliver/Documents/code/news-planner/client/node_modules/vite/dist/node/chunks/dep-BGGf7Pd3.js:696:33)
      at async Promise.all (index 0)
      at async resolveImportId (file:///Users/oliver/Documents/code/news-planner/client/node_modules/vite/dist/node/chunks/dep-BGGf7Pd3.js:629:27)
      at async parseStyles$1 (file:///Users/oliver/Documents/code/news-planner/client/node_modules/vite/dist/node/chunks/dep-BGGf7Pd3.js:537:5)
      at async Object.Once (file:///Users/oliver/Documents/code/news-planner/client/node_modules/vite/dist/node/chunks/dep-BGGf7Pd3.js:794:22)
      at async LazyResult.runAsync (/Users/oliver/Documents/code/news-planner/client/node_modules/postcss/lib/lazy-result.js:293:11)
      at async compileCSS (file:///Users/oliver/Documents/code/news-planner"client凭向后续 Vintagei:Re提升))[Spring palace
      at async TransformPluginContext.transform (file:///Users/oliver/Documents/code/news-planner/client/node_modules/vite/dist/node/chunks/dep-0AosnpPU.js:47842:11)
      at async EnvironmentPluginContainer.transform (file:///Users/oliver/Documents/code/news-planner/client/node_modules/vite/dist/node/chunks/dep-0AosnpPU.js:47219:18)
      at async loadAndTransform (file:///Users/oliver/Documents/code/news-planner/client/node_modules/vite/dist/node/chunks/dep-0AosnpPU.js:41030:27)
      at async viteTransformMiddleware (file:///Users/oliver/Documents/code/news-planner/client/node_modules/vite/dist/node/chunks/dep-0AosnpPU.js:42474:24)

尝试通过Git回滚代码、卸载重装Tailwind旧版本后，问题仍存在。系统为macOS 15.1。

1. 彻底清理依赖残留与缓存 #

• 删除node_modules目录：

  rm -rf node_modules
  

• 删除包管理器锁文件（根据使用工具选择）：

  # npm用户执行
  rm package-lock.json
  # yarn用户执行
  rm yarn.lock
  

• 清理npm缓存：

  npm cache clean --force
  

• 重新安装指定版本的Tailwind及依赖：

  npm install tailwindcss@3.4.17 autoprefixer@latest
  

2. 检查PostCSS配置文件 #

确保postcss.config.js使用Tailwind v3.x的标准配置，避免错误引入JS文件：

export default {
  plugins: {
    tailwindcss: {},
    autoprefixer: {},
  },
}

如果之前升级v4时修改过该文件，需完全恢复为上述格式。

3. 验证CSS入口文件的引入方式 #

检查项目主CSS文件（通常是src/index.css），确保使用Tailwind指令而非直接导入JS文件：

@tailwind base;
@tailwind components;
@tailwind utilities;

删除任何类似import 'tailwindcss/lib/index.js'的错误引入语句。

4. 清理Vite缓存并重启服务 #

• 手动删除Vite缓存目录：

  rm -rf .vite
  

• 强制重启Vite开发服务器：

  npm run dev -- --force
  

5. 确认Git回滚彻底 #

检查项目中所有配置文件（如vite.config.js、tailwind.config.js）是否完全回滚到升级前的状态，避免残留v4的配置代码。

内容的提问来源于stack exchange，提问作者oliver