标题不断移动到导航栏(Bootstrap)

<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/bootstrap@5.3.0/dist/css/bootstrap.min.css">
<script src="https://cdn.jsdelivr.net/npm/bootstrap@5.3.0/dist/js/bootstrap.bundle.min.js"></script>

<nav class="navbar navbar-expand-lg navbar-light bg-light fixed-top">
  <div class="container">
    <a class="navbar-brand" href="#">Logo</a>
    <button class="navbar-toggler" type="button" data-bs-toggle="collapse" data-bs-target="#navbarNav" aria-controls="navbarNav" aria-expanded="false" aria-label="Toggle navigation">
      <span class="navbar-toggler-icon"></span>
    </button>
    <div class="collapse navbar-collapse" id="navbarNav">
      <ul class="navbar-nav">
        <li class="nav-item">
          <a class="nav-link" href="#section1">Section 1</a>
        </li>
        <li class="nav-item">
          <a class="nav-link" href="#section2">Section 2</a>
        </li>
        <li class="nav-item">
          <a class="nav-link" href="#section3">Section 3</a>
        </li>
      </ul>
    </div>
  </div>
</nav>

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

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

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

.fixed-top {
  position: fixed;
  top: 0;
  width: 100%;
  z-index: 1000;
}

.container {
  margin-top: 70px; /* 导航栏高度 */
}