当我向下滚动到第三个 jumbotron 时，导航栏不起作用

Question

在我一直向下滚动到页面底部之前，我的导航栏运行良好。此时，我无法单击导航栏中的任何内容，并且我的 jumbotron 上的文字与导航栏重叠。

<html lang="en">

  <head>
    <meta charset="utf-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <link rel="stylesheet" href="/Users/Pat/Downloads/bootstrap-3.3.2-dist/css/bootstrap.css">
    <link rel="stylesheet" href="Website_Layout.css">  
    <title>Home</title>
  </head>

  <body>

    <div class="nav">
      <div class="container-fluid">
        <ul class="nav nav-pills">
          <li><a href="Website.html">Home</a></li>
          <li><a href="Projects.html">Projects</a></li>
          <li><a href="Team.html">Team</a></li>
          <li><a href="Contact.html">Contact</a></li>
        </ul>
      </div>
    </div>

    <div class="jumbotron">
      <div class="container-fluid">
        <h1>hi</h1>
        <p>hi</p>
      </div>
    </div>

    <div class="fuel">
      <div class="container-fluid">
        <h1>hi</h1>
        <p>hi</p>
      </div>  
    </div>

    <div class="learn-more">
      <div class="container-fluid">
          <div class="row">
            <div class="col-md-6">
              <h2>Development</h2>
            <p>hi</p>
            </div>
            <div class="col-md-6">
              <h2>hi</h2>
            <p>hi</p>
            </div>
          </div>
      </div>
    </div>

    <div class="nav2">
      <div class="container-fluid">
        <div class="row">
          <div class="col-md-3">
            <h1>hi</h1>
            <p>hi</p>
            <p>hi</p>
          </div>  
          <div class="col-md-3">
            <h2>hi</h2>
            <ul>
              <li><a href="Projects.html">Projects</a></li>
              <li><a href="Team.html">Team</a></li>
              <li><a href="Contact.html">Contact</a></li>
            </ul>  
          </div>  
        </div>  
      </div>
    </div>

  </body>

</html>

这是我的 CSS。

.nav {
  width: 100%;
  float: top;
  position: fixed;
  margin: 0 0 1em 0;
  padding: 0;
  background-color: black;
  height: 60px;
}
.nav ul {
  list-style: none;
  width: 100%;
  margin: 0;
  padding: 0;
  text-align: center;
}

.nav li a {
  display: block;
  padding: 20px 20px;
  color: white;
  font-size: 16px;
  text-transform: uppercase;
}

.nav li a:hover {
  color: #FF6600;
  background-color: white;
  height: 60px;
}

.jumbotron {
  background-image: url("/Users/Pat/Documents/Safron_Mountain.jpeg");
  height: 880px;
  background-repeat: no-repeat;
  background-size: cover;
  margin-bottom: 0;
}

.jumbotron h1 {
  font-size: 64px;
  text-align: center;
  color: #FF7F50;
  text-shadow: -1.2px 0 black, 0 1.2px black, 1.2px 0 black, 0 -1.2px black;
  font-weight: bold;
  font-family: 'Shift',sans-serif;
  padding-top: 15px;
  padding-bottom: 20px;
}

.jumbotron p {
  font-size: 26px;
  font-weight: bold;
  text-align: center;
}

.fuel {
  height: 800px;
  background-color: #FF7F50;
}

.fuel h1 {
  text-align: center;
  font-size: 68px;
  padding-top: 200px;
  padding-bottom: 50px;
  color: white;
  text-shadow: .3px .3px 0 #CCC, .6px .6px 0 #CCC, .9px .9px 0 #444, 1.2px 1.2px 0 #444, 1.5px 1.5px 0 #444, 1.8px 1.8px 0 #444;
}

.fuel p {
  text-align: center;
  font-size: 36px;
  padding-left: 200px;
  padding-right: 200px;
  color: white;
}

.learn-more {
  height: 800px;
}

.learn-more h2 {
  text-align: center;
  color: black;
  font-size: 60px;
  padding-top: 225px;

}

.learn-more p {
  text-align: center;
  color: black;
  font-size: 32px;
  padding-left: 50px;
  padding-right: 50px;
}

.nav2 {
  height: 150px;
  background-image: url("/Users/Pat/Downloads/footer_lodyas/footer_lodyas.png");
}

.nav2 h1 {
  font-size: 18px;
  padding-bottom: 0px;
  font-weight: bold;
  color: white;
}

.nav2 p {
  color: white;
}

.nav2 ul {
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav2 a {
  color: white;
  font-size: 14px;

}

.nav2 li a {
  display: block;
  padding: 5px 0px;
  color: white;
}

.nav2 h2 {
  font-size: 18px;
  font-weight: bold;
  color: white;
}

感谢大家的帮助！

Answer 1

试着把它放在你的 .nav 中的 CSS

.nav {
    z-index: 100;
}