index.php

<html>
<head>
    <meta charset="utf-8">
    <title> Index </title>
        <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/css/bootstrap.min.css">
        <link rel="stylesheet" href="css/style.css">
        <link rel="stylesheet" href="css/animate.css"
</head>
    <body>
    <div class="container">
        <div id="slidebottom" class="fixed-bottom btn-toolbar"> <!-- panel-footer -->
            <button id="btn"  type="button" class="btn btn-lg btn-light">Question one</button>
            <button id="btn2" type="button" class="btn btn2 btn-lg btn-light">Colors</button>
            <button id="btn3" type="button" class="btn btn3 btn-lg btn-light">Gallery</button>
            <!-- end panel-footer-->
        </div>

        <div id="slideup" class="box-popup" style="display:none;">
            <h2>How are u doing?</h2>
        </div>
    </div>

    <script type="text/javascript" src="js/jquery-3.3.1.min.js"></script>
    <script type="text/javascript" src="js/jfunc.js"></script>
    <script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/js/bootstrap.min.js" integrity="sha384-JZR6Spejh4U02d8jOt6vLEHfe/JQGiRRSQQxSfFWpi1MquVdAyjUar5+76PVCmYl" crossorigin="anonymous"></script>

    </body>
</html>