手机端适配

(function (designWidth, maxWidth) {
var doc = document,
win = window;
var docEl = doc.documentElement;
var tid;
var rootItem, rootStyle;

function refreshRem() {
var width = docEl.getBoundingClientRect().width;
if (!maxWidth) {
maxWidth = 540;
}
if (width > maxWidth) {
width = maxWidth;
}
//与淘宝做法不同，直接采用简单的rem换算方法1rem=100px
var rem = width * 100 / designWidth;
//兼容UC开始
rootStyle = "html{font-size:" + rem + 'px !important}';
rootItem = document.getElementById('rootsize') || document.createElement("style");
if (!document.getElementById('rootsize')) {
document.getElementsByTagName("head")[0].appendChild(rootItem);
rootItem.id = 'rootsize';
}
if (rootItem.styleSheet) {
rootItem.styleSheet.disabled || (rootItem.styleSheet.cssText = rootStyle)
} else {
try {
rootItem.innerHTML = rootStyle
} catch (f) {
rootItem.innerText = rootStyle
}
}
//兼容UC结束
docEl.style.fontSize = rem + "px";
};
refreshRem();

win.addEventListener("resize", function () {
clearTimeout(tid); //防止执行两次
tid = setTimeout(refreshRem, 300);
}, false);

win.addEventListener("pageshow", function (e) {
if (e.persisted) { // 浏览器后退的时候重新计算
clearTimeout(tid);
tid = setTimeout(refreshRem, 300);
}
}, false);

if (doc.readyState === "complete") {
doc.body.style.fontSize = "16px";
} else {
doc.addEventListener("DOMContentLoaded", function (e) {
doc.body.style.fontSize = "16px";
}, false);
}
})(750, 750);

<meta name="viewport"   content="width=device-width, initial-scale=1, maximum-scale=1, user-scalable=no">