移动端适配rem

750px的设计图 1rem=200px 自适应机型

!function(b, a){
var c = b.documentElement;
a = function() {
var a = c.clientWidth;
a && (c.style.fontSize = a/375 * 100 + "px")
};
window.addEventListener("orientationchange" in window ? "orientationchange" : "resize", a, !1);
b.addEventListener("DOMContentLoaded", a, !1)
}(document, window);