rem根据屏幕大小适配字体大小

(function(window, document) {function rootSize() {var screenWidth = document.documentElement.clientWidth || window.innerWidth;//        console.log(screenWidth);var rootSize = screenWidth > 750 ? 100 :screenWidth < 320 ? 320 / 750 * 100 : screenWidth / 750 * 100;document.documentElement.style.fontSize = rootSize + 'px';}//        window.addEventListener('DOMContentLoaded',rootSize);window.onload = function() {rootSize();};window.onresize = function() {rootSize();}
})(window, document);