JS Crawl screen width set font size REM

var doc = Window.document
var docel = doc.documentelement
var tid

function Refreshrem () {
var width = docel.getboundingclientrect (). Width
if (Width > 540) {//Max width
width = 540
}
var rem = width/7.5//The screen width is divided into 750 parts, 1 parts for 1rem 375 screen just 0.5px
docEl.style.fontSize = rem + ' px '
}

Window.addeventlistener (' Resize ', function () {
Cleartimeout (TID)
Tid = SetTimeout (Refreshrem, 300)
}, False)
Window.addeventlistener (' Pageshow ', function (e) {
if (e.persisted) {
Cleartimeout (TID)
Tid = SetTimeout (Refreshrem, 300)
}
}, False)

Refreshrem ()

JS Crawl screen width set font size REM