vue3_element_demo1/src/main.js

import {createApp} from 'vue'
import ElementPlus from 'element-plus'  // 完整引入Element-Plus
import 'element-plus/lib/theme-chalk/index.css'  // 引入样式文件
import App from './App.vue'

const app = createApp(App)
app.use(ElementPlus, {size: 'small', zIndex: 3000})
app.mount('#app')