Today I tried to check my site using Google PageSpeed Insights and in it's recommendations was: "Eliminate render-blocking CSS in above-the-fold content". As I understand it's better to include all CSS for top part of the page (for example in <head> tag) and then include styles for other content later on the page. In docs for this recommendation was this example construction:
<html>
<head>
<style>
.blue{color:blue;}
</style>
</head>
<body>
<div class="blue">
Hello, world!
</div>
</body>
</html>
<link rel="stylesheet" href="small.css">
But the problem is that HTML W3 validator throws and error ("Stray start tag link") the same is when I'm trying to include <link> inside <body> tags. So the question is: What's the better way to include CSS into the page (is it normal to use recommended construction or no)?