→ section 2.1
<div align='center'>
<img class="img-responsive" src=url width="75%" id="id">
<p>
Figure x.x title
</p>
</div>
<div class="col-sm-3 col-sm-offset-3 blog-sidebar">
<div class="menu sticky" style="position: sticky; top: 60px;">
<br />
<br />
<h3><em>CONTENTS</em></h3>
<br />
<br />
<ul>
<li class="list-inline">
<a class="text-muted" href="#1"><h5>1</h5></a>
</li>
<li class="list-inline">
<a class="text-muted" href="#2"><h5>2</h5></a>
</li>
<li class="list-inline">
<a class="text-muted" href="#3"><h5>3</h5></a>
</li>
</ul>
<div class="sidebar-module">
<br />
<br />
<h3><em>ELSEWHERE</em></h3>
<ol class="list-unstyled">
<li>
<a href="https://github.com/Trancemania" title="GitHub" class="btn btn-social-icon btn-lg btn-github"><span class="fa fa-github"></span></a>
<a href="https://www.facebook.com/people/Zhao-Hong-Wang/100007906816276" title="facebook" class="btn btn-social-icon btn-lg btn-facebook"><span class="fa fa-facebook"></span></a>
</li>
</ol>
</div>
</div>
</div>
<small class="h6">
<button type="button" class="btn" data-toggle="modal" data-target="#modal_id">
launch button title
</button>
</small>
<!-- Modal -->
<div class="modal fade" id="modal_id" tabindex="-1" role="dialog" aria-labelledby="modal_id_label" aria-hidden="true">
<div class="modal-dialog" role="document">
<div class="modal-content">
<div class="modal-header">
<h5 class="modal-title" id="modal_id_label">modal title</h5>
<button type="button" class="close" data-dismiss="modal" aria-label="Close">
<span aria-hidden="true">×</span>
</button>
</div>
<div class="modal-body">
modal content
</div>
<div class="modal-footer">
<button type="button" class="btn btn-secondary" data-dismiss="modal">Close</button>
<button type="button" class="btn btn-primary">Save changes</button>
</div>
</div>
</div>
</div>