如果想迎合谷歌的网站优化建议的话,弹出这个提示的时候,看国语翻译基本上是没啥帮助的,所以还是看看英语翻译吧:
https://developers.google.com/speed/docs/insights/OptimizeCSSDelivery
示例代码如下:

<html>
<head>
<style>
.blue{color:blue;}
</style>
</head>
<body>
<div class="blue">
Hello, world!
</div>
<script>
var cb = function() {
var l = document.createElement('link'); l.rel = 'stylesheet';
l.href = 'small.css';
var h = document.getElementsByTagName('head')[0]; h.parentNode.insertBefore(l, h);
};
var raf = requestAnimationFrame || mozRequestAnimationFrame ||
webkitRequestAnimationFrame || msRequestAnimationFrame;
if (raf) raf(cb);
else window.addEventListener('load', cb);
</script>
</body>
</html>

Related Posts: 清除首屏内容中阻止呈现的CSS :