只需在main.js    ====import './style.less'
 
main.js =》》
 
import Vue from 'vue'
import App from './App.vue'
import router from './router'
import store from './store'

Vue.config.productionTip = false

import './style.less'

new Vue({
router,
store,
render: h => h(App)
}).$mount('#app')
 
引入的less,这样就可以使用了
 
.hello{
h1 {
color: yellow;
}
}