如何在与标题相同的行上添加导航栏？

<nav>
  <ul>
    <li><a href="#section1">Section 1</a></li>
    <li><a href="#section2">Section 2</a></li>
    <li><a href="#section3">Section 3</a></li>
  </ul>
</nav>

nav {
  background-color: #f2f2f2;
  padding: 10px;
}

nav ul {
  list-style-type: none;
  margin: 0;
  padding: 0;
}

nav ul li {
  display: inline;
}

nav ul li a {
  text-decoration: none;
  padding: 5px 10px;
  color: #333;
}

nav ul li a:hover {
  background-color: #333;
  color: #fff;
}

<h1 id="section1">Section 1</h1>
<p>Content of section 1</p>

<h1 id="section2">Section 2</h1>
<p>Content of section 2</p>

<h1 id="section3">Section 3</h1>
<p>Content of section 3</p>