Today's code - position : fixed
<body>
<div id="wrap">
<h1>HTML (Hyper Text Markup Language) </h1>
<nav>
<ul class="gnb">
<li><a href="#history">History</a></li>
<li><a href="#markup">Markup</a></li>
<li><a href="#semantic">Semantic HTML</a></li>
</ul>
</nav>
<section id="history">
<h2>History</h2>
<p>...</p>
</section>
<section id="markup">
<h2>Markup</h2>
<p>...</p>
</section>
<section id="semantic">
<h2>Semantic HTML</h2>
<p>...</p>
</section>
</div>
</body>
[nav]
[nav>.gnb]