过去：
<div class="header">
<div class="hgroup">
<h1>....</h1>
<h2>....</h2>
</div>
<div class="nav">
<ul>
<li>....</li>
<li>....</li>
<li>....</li>
<li>....</li>
</ul>
</div>
</div>
<div class="article">
<div class="section">....</div>
<div class="section">....</div>
<div class="section">....</div>
<div class="section">....</div>
</div>
<div class="aside">....</div>
<div class="footer">....</div>
现在：
<header>
<hgroup>
<h1>....</h1>
<h2>....</h2>
</hgroup>
<nav>
<ul>
<li>....</li>
<li>....</li>
<li>....</li>
<li>....</li>
</ul>
</nav>
</header>
<article>
<section>....</section>
<section>....</section>
<section>....</section>
<section>....</section>
</article>
<aside>....</aside>
<footer>....</footer>