Transition effects Top vs. Bottom in CSS is not working - css

Question

Well, this is my first topic here, so here it is!
I've just done a nice-simple :hover code where you can mouse over an image and the captions underneath it appears for complete. More specifically, in this code I have two types of captions, one above the image and one right underneath the image, which can be found when you mouse it over.
The :hover works pretty fine, however I need to add a simple effect, just a little linear transition. So I add the most basic transitions in the "a" tag, but it is not working at all! I guess the code is not recognizing the top:0px in the .featured-banner a class and the bottom:0px in the .featured-banner a:hover.
Does anyone have a solution for it? I appreciate you guys for helping me out!
Oh, just in case, the text inside the captions classes are written in portuguese but not very interesting, just an ad for Cancun! =P
Here is the HTML i'm using:
<div class="featured-banner">
<a href="#">
<div class="caption">
<p>Mega Oferta • Cancún • Carnaval 2014</p>
</div>
<img src="http://www.advtour.com.br/sample-cancun.jpg" />
<div class="under-caption">A partir de US$ 2.148 Ou entrada + 11x de R$ 358</div>
</a>
And here is the CSS:
.featured-banner {
width:930px;
height:350px;
background:#000;
font-family:sans-serif;
font-size:23px;
margin:14px 0px;
overflow:hidden;
position:relative;
}
.featured-banner a {
text-decoration:none;
position:absolute;
top:0;
-webkit-transition:all 1s ease;
-moz-transition:all 1s ease;
-ms-transition:all 1s ease;
-o-transition:all 1s ease;
transition:all 1s ease;
}
.featured-banner a:hover {
top:inherit;
bottom:0;
}
.caption {
width:100%;
height:350px;
color:#FFF;
text-transform:uppercase;
position:absolute;
top:0px;
z-index:98;
}
.caption p {
width:97%;
background:rgba(0,0,0, .4);
color:#FFF;
text-align:justify;
text-transform:uppercase;
background:rgba(0,0,0, .4);
padding:11px 14px;
position:absolute;
bottom:0px;
z-index:98;
}
.under-caption {
width:97%;
background:rgba(0,0,0, .4);
color:#FFF;
font-size:20px;
text-align:justify;
background:rgba(0,0,0, .4);
padding:11px 14px;
z-index:98;
}
Here is a demo

Answer 1

If you are going to transition the effect then you need to transition the same style. Going from top - bottom will cause no transition since it is changing the styles. If you did top: 0; to top: 100%; then you will see a transition.
Here is the css I changed:
.featured-banner a {
text-decoration:none;
position:absolute;
top:0;
-webkit-transition:all 1s ease;
-moz-transition:all 1s ease;
-ms-transition:all 1s ease;
-o-transition:all 1s ease;
transition:all 1s ease;
}
.featured-banner a:hover {
top:inherit;
top: -55px;
}
Finally, a fiddle: Demo

Answer 2

You can only transition the same attribute. Top and bottom aren't the same.
I worked out a fiddle, which shows how it could work.
.under-caption {
position: absolute;
width:97%;
background:rgba(0,0,0, .4);
color:#FFF;
font-size:20px;
text-align:justify;
background:rgba(0,0,0, .4);
padding:11px 14px;
z-index:98;
bottom: -3em;
-webkit-transition:bottom 1s ease;
-moz-transition:bottom 1s ease;
-ms-transition:bottom 1s ease;
-o-transition:bottom 1s ease;
transition:bottom 1s ease;
}
.featured-banner:hover .under-caption{
bottom: 1em;
}
http://jsfiddle.net/u3E5P/1/