Please include following css file at head element

                                                            <!-- Quill css -->
<link href="assets/vendor/quill/quill.core.css" rel="stylesheet" type="text/css" />
<link href="assets/vendor/quill/quill.snow.css" rel="stylesheet" type="text/css" />
                                                        

Make sure to include following js files at end of body element

                                                            <!-- quill js -->
<script src="assets/vendor/quill/quill.min.js"></script>
<!-- quill Init js-->
<script src="assets/js/pages/demo.quilljs.js"></script>
                                                        

                                                            <!-- HTML -->
<div id="snow-editor" style="height: 300px;">
    <h3><span class="ql-size-large">Hello World!</span></h3>
    <p><br></p>
    <h3>This is an simple editable area.</h3>
    <p><br></p>
    <ul>
        <li>
            Select a text to reveal the toolbar.
        </li>
        <li>
            Edit rich document on-the-fly, so elastic!
        </li>
    </ul>
    <p><br></p>
    <p>
        End of simple area
    </p>
</div>
                                                        

Please include following css file at head element

                                                            <!-- Quill css -->
<link href="assets/vendor/quill/quill.bubble.css" rel="stylesheet" type="text/css" />
                                                        

                                                            <div id="bubble-editor" style="height: 300px;">
    <h3><span class="ql-size-large">Hello World!</span></h3>
    <p><br></p>
    <h3>This is an simple editable area.</h3>
    <p><br></p>
    <ul>
        <li>
            Select a text to reveal the toolbar.
        </li>
        <li>
            Edit rich document on-the-fly, so elastic!
        </li>
    </ul>
    <p><br></p>
    <p>
        End of simple area
    </p>
</div>