Setting the height on a border in CSS - html

Question

I have a left/right border on a list to create a separation effect.
Ex: Link1 | Link2 | ...
I want the lines on the border to be a bit shorter than the total height of the object -- maybe 50% of the total height and centered vertically. However, they are 100% of height. How can I set a height on a border and center it vertically?
Thanks!
<ul class="nav pull-right" style="line-height:30px;">
<li class="dropdown pull-right" style="line-height:20px;border-left: 1px solid #e3e3e3;border-right: 1px solid #e3e3e3;">
<a href="#" class="dropdown-toggle" data-toggle="dropdown">
{% if notice_unseen_count %} <span class="badge badge-warning" style="line-height:15px;">{{ notice_unseen_count }}</span>{% else %}<span class="badge" style="line-height:15px;">0</span>{% endif %}
</a>
<ul class="dropdown-menu">
<li>Inbox</li>
<li class="divider"></li>
<li>Invitations</li>
<li class="divider"></li>
<li>All Notifications</li>
</ul>
</li>

Answer 1

Don't blow up your list with a divider-element. Try this. You can easily adjust the size/height of the border that is created by using the :after pseudo element:
Demo
Try before buy
HTML
<ul>
<li>Inbox</li>
<li>Invitations</li>
<li>All Notifications</li>
</ul>
CSS
ul {
margin: 0;
padding 0;
list-style: none;
}
ul > li {
float: left;
height: 30px;
line-height: 30px;
background: red;
}
ul > li:after {
content: '';
display:block;
float: right;
height: 15px;
width: 1px;
background: #ccc;
margin: 7px 10px 0 10px;
}
Last "border"
To remove the border from the last element, this CSS rule does the job:
ul > li:last-child:after {
content: none;
}

Answer 2

The border lengths will always be >= element's width/height, so you cannot set it to 50% or anything. See the box model: http://css-tricks.com/the-css-box-model/
If you want to style those separation bars, suggest using a background image.
.divider {
background: transparent url('link/to/separator.gif') right center no-repeat;
padding: auto 10px;
}
This will add separater image to the right of all the links with divider class. For the last item in the list, you don't need to apply the class.