Development projects need adaptive pages
We can create... In the root directory utils Folder , Create in folder rem.js file

// Set up rem function
(function () {
function setRem () {
// 1920 Default size 16px; Every element px On the basis of /16
const htmlWidth = document.documentElement.clientWidth || document.body.clientWidth
document.documentElement.style.fontSize = htmlWidth * 16 / 1920 + 'px'
}
// initialization
setRem()
window.addEventListener('resize', setRem, false)
})()

Then introduce to main.js

import '@/utils/rem'