移动端rem单位转换

        <script>
        function fontSize(px) {
        var winWidth = window.innerWidth;
        var winHeight = window.innerHeight;
        var oHtml = document.querySelector("html");
        var oBody = document.querySelector("body");
        px = px || 1080;
        var fontsize;
        if (winWidth < 320) {
            fontsize = 10;
        } else if (320 <= winWidth && winWidth <= 750) {
            fontsize = winWidth * 0.0625;
        } else {
            fontsize = px * 0.0625; //46.875
        }
        oHtml.style.fontSize = fontsize + "px";
        if (winWidth == 414) {
            oHtml.dataset.dpr = 3;
            fontsize = winWidth * 2 / 3 * 0.0625 + "px";
        } else {
            oHtml.dataset.dpr = 2;
        }

        if (oBody) {
            oBody.style.width = winWidth + "px";
            oBody.style.height = winHeight + "px";
        }
        return fontsize;
    }

    (function () {
        function o() {
            fontSize(414);
        }
        var e = null;
        window.addEventListener("resize", function () {
            clearTimeout(e), e = setTimeout(o, 300)
        }, !1), o()
    })(window);
    </script>