<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0">
<script>
(function (doc, win) {
var docEl = doc.documentElement,
resizeEvt = 'orientationchange' in window ? 'orientationchange' : 'resize',
recalc = function () {
var clientWidth = docEl.clientWidth;
if (!clientWidth) return;
if (clientWidth >= 640) {
docEl.style.fontSize = '100px';
} else {
docEl.style.fontSize = 100 * (clientWidth / 640) + 'px';
}
};
if (!doc.addEventListener) return;
win.addEventListener(resizeEvt, recalc, false);
doc.addEventListener('DOMContentLoaded', recalc, false);
})(document, window);
</script>
<title>Title</title>
</head>
<body>
</body>
</html>
這段代碼會(huì)自動(dòng)計(jì)算html上的font-size,640即設(shè)計(jì)稿的寬度,然后所有寫的代碼數(shù)值直接除以100,比如一個(gè)元素再設(shè)計(jì)稿上的寬度為200px; 那css寫的時(shí)候?yàn)?rem
如果設(shè)計(jì)稿的寬度是1280px, 640 即改為1280,若是div設(shè)計(jì)稿為200200px,那么css寫為22rem