index.html

<!DOCTYPE html>
<html>
<head lang="en">
    <meta charset="UTF-8">
    <title>学习文件</title>
    <link href="css/assets/bootstrap/css/bootstrap.css" rel="stylesheet">
    <style>
        div a {
            text-align: center;
        }
    </style>
</head>
<body>

    <div class="list-group">

        <a href="css/lianjie.html" class="list-group-item">
            CSS
        </a>
        <a href="JS/index.html" class="list-group-item">
            JS
        </a>
        <a href="正则表达式/正则/正则表达式.html" class="list-group-item">
            正则表达式
        </a>
        <a href="DOMandBOM/" class="list-group-item">
            DOM和BOM
        </a>

    </div>


    <script src="css/assets/jquery/jquery.js"></script>
    <script src="css/assets/bootstrap/js/bootstrap.min.js"></script>
</body>
</html>