Phantom spacing with collapsible side nav and Bootstrap 3 - html

Question

I'm having a little trouble getting a collapsible side nav built with Bootstrap 3 to behave on a site I'm working on. I've started getting way too much vertical space between <li>s but I can't figure out where it's coming from. I thought it might be from Wordpress adding <p> and <br> tags and while that certainly isn't helping it also doesn't seem to be the primary problem.
A sample URL is:
http://cbipath.com/arabic/aa-tax-regulations-that-protect-the-rich/
And the code in question is:
(Note that this is still a work in progress, so it's rife with broken links etc.)
<div class="col-xs-6 col-sm-3 sidebar-offcanvas" id="sidebar" role="navigation">
<div class="sidebar-nav">
<p class="sidenav-header">
Units and Lessons:
</p>
<ul class="nav nav-list accordion" id="sidenav-accordion">
<li>
<div class="accordion-heading">
<a data-toggle="collapse" data-target="#content-areas"><span class="nav-header-primary">
Content Areas <i class="icon-chevron-right"></i>
</span></a>
</div>
<ul class="nav nav-list collapse" id="content-areas">
<li>All <i class="icon-chevron-right"></i>
</li>
<li>
<div class="accordion-heading">
<a class="accordion-toggle" data-toggle="collapse" data-parent="#content-areas" href="#nav-urban-planning"><span class="nav-header-secondary">
Urban Planning <i class="icon-chevron-right"></i></span></a>
</div>
<ul class="nav-tertiary nav-list collapse" id="nav-urban-planning">
<li>Introduction
</li>
<li>Urban Planning 1
</li>
<li>Urban Planning 2
</li>
<li>Urban Planning 3
</li>
<li>Urban Planning 4
</li>
</ul>
</li>
<li>
<div class="accordion-heading">
<a class="accordion-toggle" data-toggle="collapse" data-parent="#content-areas" href="#nav-sustainability"><span class="nav-header-secondary">
Sustainability <i class="icon-chevron-right"></i></span></a>
</div>
<ul class="nav-tertiary nav-list collapse" id="nav-sustainability">
<li>Introduction
</li>
<li>Sustainability 1
</li>
<li>Sustainability 2
</li>
<li>Sustainability 3
</li>
<li>Sustainability 4
</li>
</ul>
</li>
<li>
<div class="accordion-heading">
<a class="accordion-toggle" data-toggle="collapse" data-parent="#content-areas" href="#nav-public-administration"><span class="nav-header-secondary">
Public Administration <i class="icon-chevron-right"></i></span></a>
</div>
<ul class="nav-tertiary nav-list collapse" id="nav-public-administration">
<li>Introduction
</li>
<li>Public Administration 1
</li>
<li>Public Administration 2
</li>
<li>Public Administration 3
</li>
<li>Public Administration 4
</li>
</ul>
</li>
<li>
<div class="accordion-heading">
<a class="accordion-toggle" data-toggle="collapse" data-parent="#content-areas" href="#nav-health"><span class="nav-header-secondary">
Health <i class="icon-chevron-right"></i></span></a>
</div>
<ul class="nav-tertiary nav-list collapse" id="nav-health">
<li>Introduction
</li>
<li>Lesson: What is Epilepsy? (Turkish)
</li>
<li>Lesson: Pathology (Turkish)
</li>
</ul>
</li>
</ul>
<!-- End Content Areas Internal UL -->
</li>
<!-- End Content Areas List Item-->
<li>
<!-- Begin Languages List Item-->
<div class="accordion-heading">
<a data-toggle="collapse" data-target="#languages"><span class="nav-header-primary">
Languages <i class="icon-chevron-right"></i>
</span></a>
</div>
<ul class="nav nav-list collapse" id="languages">
<li>All <i class="icon-chevron-right"></i>
</li>
<li>
<div class="accordion-heading">
<a class="accordion-toggle" data-toggle="collapse" data-parent="#languages" href="#nav-arabic"><span class="nav-header-secondary">
Arabic <i class="icon-chevron-right"></i></span></a>
</div>
<ul class="nav-tertiary nav-list collapse" id="nav-arabic">
<li>Overview
</li>
<li>Education and Democracy in the Arab World
</li>
<li>Tax Regulations that Protect the Rich
</li>
<li>Minorities in the Arab World
</li>
<li>Revolution, Equality, and Women's Rights
</li>
</ul>
</li>
<li>
<div class="accordion-heading">
<a class="accordion-toggle" data-toggle="collapse" data-parent="#languages" href="#nav-turkish"><span class="nav-header-secondary">
Turkish <i class="icon-chevron-right"></i></span></a>
</div>
<ul class="nav-tertiary nav-list collapse" id="nav-turkish">
<li>Overview
</li>
<li>Lesson: What is Epilepsy?
</li>
<li>Lesson: Pathology
</li>
<li>Lesson: Pathology
</li>
</ul>
</li>
<li>
<div class="accordion-heading">
<a class="accordion-toggle" data-toggle="collapse" data-parent="#languages" href="#nav-hebrew"><span class="nav-header-secondary">
Hebrew <i class="icon-chevron-right"></i></span></a>
</div>
<ul class="nav-tertiary nav-list collapse" id="nav-hebrew">
<li>Overview
</li>
<li>Israel's Declaration of Independence
</li>
</li>
</ul>
</li>
</ul>
</li>
<!-- End Languages List Item-->
</ul>
</div>
I've been staring at this for awhile now -- any help would be appreciated.
EDIT: To be more specific -- I'd like to decrease the vertical space between the items. They seem to be getting arbitrarily high heights but when I try to specify a height it breaks the collapse action.

Answer 1

Answering my own here:
This was caused by <br> tags getting inserted into the code. This comes up from time to time with Wordpress and can usually be handled by adding two lines of code to functions.php as instructed here:
http://codex.wordpress.org/Function_Reference/wpautop
I have that in my functions.php, so it seems likely that they were being inserted due to a plugin (I haven't definitively figured out which one yet). A temporary fix is adding:
.sidebar-nav br {
display: none;
}
to the custom CSS file. It seems likely these are getting added by the PageBuilder plugin by SiteOrigin which is otherwise a really great plugin. I'll update here if I'm able to definitively establish that.