根据 HTML5 规范，在引入 CSS 和 JavaScript 文件时一般不需要指定 `type` 属性，因为 `text/css` 和 `text/javascript` 分别是它们的默认值。 #### HTML5 spec links * [Using link](http://www.w3.org/TR/2011/WD-html5-20110525/semantics.html#the-link-element) * [Using style](http://www.w3.org/TR/2011/WD-html5-20110525/semantics.html#the-style-element) * [Using script](http://www.w3.org/TR/2011/WD-html5-20110525/scripting-1.html#the-script-element) ~~~ <!-- External CSS --> <link rel="stylesheet" href="code-guide.css"> <!-- In-document CSS --> <style> /* ... */ </style> <!-- JavaScript --> <script src="code-guide.js"></script> ~~~