animating pseudo element when passing to another element - css

Question

I got a pseudo-element that marks the user's current choice in a navigation bar. It's a small upward triangle, an icon font from Font-Awesome. here's a jsFiddle DEMO of it (you need to stretch the result panel so everything will be lined).
.subnav > ul > li.active > a:after {
position: relative;
text-align: center;
font-family: FontAwesome;
top: 25px;
right: 50%;
content: "\f0de";
color: #c1c1c1;
}
I've added some basic jQuery function that switches the .active class, and I'm wondering if there's a way to animate the transition of the pseudo element so it'll move horizontally to the new position.
I know pseudo-elements transition are a thing, but searching and googling around I couldn't find anything similar to what I'm looking for. Is this even possible?

Answer 1

In this solution I used the :target pseudo class to switch states, but I recommend you stick with the jQuery function that switches the .active class.
FIDDLE
Markup
<div class="page" id="one">page one</div>
<div class="page" id="two">page two</div>
<div class="page" id="three">page three</div>
<div class="top">
<div class="arrow"></div>
<ul>
<li>One</li>
<li>Two</li>
<li>Three</li>
</ul>
</div>
CSS
.top
{
background: #eee;
position:relative;
overflow: hidden;
}
.arrow
{
border-bottom: 1px solid #c2c2c2;
height: 50px;
}
.arrow:before
{
content: '';
display: block;
width: 14px;
height: 14px;
border: 1px solid #c2c2c2;
border-radius: 3px;
position:absolute;
bottom:-9px;
left: 30px;
background: #fff;
-webkit-transform: rotate(45deg);
-moz-transform: rotate(45deg);
-ms-transform: rotate(45deg);
-o-transform: rotate(45deg);
transform: rotate(45deg);
-webkit-transition: left, 0.5s;
-moz-transition: left, 0.5s;
-o-transition: left, 0.5s;
transition: left, 0.5s;
}
ul
{
position: absolute;
top: 0;
list-style: none;
padding-left: 20px;
margin-top: 15px;
}
li
{
display: inline-block;
text-decoration: none;
font-size: 18px;
color: #676767;
margin-right: 40px;
}
.page
{
width: 100%;
height: 200px;
position: absolute;
top: 80px;
opacity: 0;
background: yellow;
-webkit-transition: opacity, 0.5s;
-moz-transition: opacity, 0.5s;
-o-transition: opacity, 0.5s;
transition: opacity, 0.5s;
}
.page:target
{
opacity: 1;
}
#two
{
background: pink;
}
#three
{
background: brown;
}
#one:target ~ .top .arrow:before
{
left: 30px;
}
#two:target ~ .top .arrow:before
{
left: 105px;
}
#three:target ~ .top .arrow:before
{
left: 189px;
}