기본형 [속성]
<html>
<title>
</title>
<style>
a[href] {
background: yellow;
}
</style>
<body>
<section id="container">
<ul>
<li><a>메인 메뉴 1</a></li>
<li><a href="#">메인 메뉴 1</a></li>
</ul>
</section>
</body>
</html>