body{
background: url(adam-griffith-sWkkIiTJMYc-unsplash.jpg);
background-size:cover;
background-position: center;
font-family: Lato;
color:white;
}
html{
height: 100%;
}
#content{
text-align:center;
padding-top: 25%;
text-shadow: 0px 4px 3px rgba(0,0,0,0.4),
0px 8px 13px rgba(0,0,0,0.1),
0px 18px 23px rgba(0,0,0,0.1);
}
h1{
font-weight: 700;
font-size: 5em;
}
hr{
width: 400px;
border-top: 1px solid #f8f8f8;
border-bottom:1px solid rgba(0,0,0,0.2);
}<!DOCTYPE html>
<html>
<head>
<title>Purrfect Match</title>
<link href="https://fonts.googleapis.com/css?family=Lato:400,700&display=swap" rel="stylesheet">
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css" integrity="sha384-BVYiiSIFeK1dGmJRAkycuHAHRg32OmUcww7on3RYdg4Va+PmSTsz/K68vbdEjh4u" crossorigin="anonymous">
<link rel="stylesheet" type="text/css" href="index.css">
<link rel="stylesheet" type="text/css" href="https://maxcdn.bootstrapcdn.com/font-awesome/4.4.0/css/font-awesome.min.css">
</head>
<body>
<nav class="navbar navbar-default">
<div class="container">
<!-- Brand and toggle get grouped for better mobile display -->
<div class="navbar-header">
<button type="button" class="navbar-toggle collapsed" data-toggle="collapse" data-target="#bs-example-navbar-collapse-1" aria-expanded="false">
<span class="sr-only">Toggle navigation</span>
<span class="icon-bar"></span>
<span class="icon-bar"></span>
<span class="icon-bar"></span>
</button>
<a class="navbar-brand" href="index.html">Purrfect Match</a>
</div>
<!-- Collect the nav links, forms, and other content for toggling -->
<div class="collapse navbar-collapse" id="bs-example-navbar-collapse-1">
<ul class="nav navbar-nav">
<li><a href="about_index.html">About</a></li>
<li><a href="contact.html">Contact</a></li>
<li class="nav-item">
<a class="nav-link" href="imageGallery.html">Gallery</a>
</li>
</ul>
<ul class="nav navbar-nav navbar-right">
<li><a href="online_signup.html">Sign in <i class="fa fa-user-plus"></i></a></li>
</ul>
</div><!-- /.navbar-collapse -->
</div><!-- /.container-fluid -->
</nav>
<div class="container">
<div class="row">
<div class="col-lg-12">
<div id="content">
<h1>Purrfect Match</h1>
<h3>The Only Human-Canine Dating App</h3>
<hr>
<button class="btn btn-default btn-lg" onclick ="window.location.href = 'quiz.html';"><i class="fa fa-paw"></i> Get Started</button>
</div>
</div>
</div>
</div>
<script
src="https://code.jquery.com/jquery-2.2.4.min.js"
integrity="sha256-BbhdlvQf/xTY9gja0Dq3HiwQF8LaCRTXxZKRutelT44="
crossorigin="anonymous"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js" integrity="sha384-Tc5IQib027qvyjSMfHjOMaLkfuWVxZxUPnCJA7l2mCWNIpG9mGCD8wGNIcPD7Txa" crossorigin="anonymous"></script>
</body>
</html>我似乎无法在我的笔记本电脑上使bootstrap工作。我已经尝试在本地添加它。这里是通过互联网链接的代码。我已经尝试了一切。连接它在每一个可能的方式，它只是没有意义，为什么它会工作在我的朋友的笔记本电脑，但不是在我的。我已经搜索了所有通过谷歌，所以你们是我最后的赌注。请帮助我
尝试添加这个链接。
<link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/css/bootstrap.min.css"
rel="stylesheet"
integrity="sha256-MfvZlkHCEqatNoGiOXveE8FIwMzZg4W85qfrfIFBfYc= sha512-dTfge/zgoMYpP7QbHy4gWMEGsbsdZeCXz7irItjcC3sPUFtf0kuFbDz/ixG7ArTxmDjLXDmezHubeNikyKGVyQ=="
crossorigin="anonymous">