function createStyle(){    return"*{padding:0;margin:0;border:0}.loading{width:640px;height:1024px;margin:0 auto}.loadImg{width:640px;height:1024px;animation:fadeInOut 3s linear;-webkit-animation:fadeInOut 3s linear;-moz-animation:fadeInOut 3s linear;opacity:0}@keyframes fadeInOut{0%{opacity:0}25%{opacity:.5}45%{opacity:1}50%{opacity:1}55%{opacity:1}75%{opacity:.5}100%{opacity:0}}@-moz-keyframes fadeInOut{0%{opacity:0}25%{opacity:.5}45%{opacity:1}50%{opacity:1}55%{opacity:1}75%{opacity:.5}100%{opacity:0}}@-webkit-keyframes fadeInOut{0%{opacity:0}25%{opacity:.5}45%{opacity:1}50%{opacity:1}55%{opacity:1}75%{opacity:.5}100%{opacity:0}}"}function addStyle(){    var style = document.createElement("style");    style.type = "text/css";    style.innerHTML = createStyle();    window.document.head.appendChild(style);}function addDom(){    var div = document.createElement("div");    div.className = "loading";    window.document.body.appendChild(div);    var img = document.createElement("img");    img.src="img/bg.png";    img.id="loadImg";    img.className="loadImg";    div.appendChild(img);}window.onload=function(){    addStyle();    addDom();}