function getRem(pwidth,prem){
	var html = document.getElementsByTagName("html")[0];
	var oWidth = document.body.clientWidth || document.documentElement.clientWidth;
	var size=oWidth/pwidth*prem;
	html.style.fontSize = size + "px";
}
$(document).ready(function(){
	//画布、字体大小设定
    getRem(750,100);
    $(window).resize(function() {
        getRem(750,100);
    })
});