I want to get this when resizing the browser window:

And I have this HTML:
<a class="article-link-block" href="#">
<img src="http://c69282.r82.cf3.rackcdn.com/361.jpg">
<div class="article-info">
Article Info need to be 20% of the height and always at the bottom
</div>
</a>
I can get everything but not the 20% of the height for article info.
I can only make it e.g. 50px height and then margin-top: -50px and it is ok, for maximum width. but when I start decreasing the width of the browser it doesn’t change the height only the width, which is 100%.
Any advice/techique how can I dynamically resize height and stay at the bottom all the time?
If I use margin-top: -20%; height: 20%; for .article-info
it creates something like that:

But this is wrong, of course.
Btw. CSS is
.article-link-block {
display: block;
float: left;
width: 100%;
position: relative;
height: auto;
}
.article-link-block img {
margin: 0px;
padding: 0px;
display: block;
float: left;
}
.article-info {
background: black;
width: 100%;
height: auto;
float: left;
position: relative;
display: block;
margin-top: -20%;
height: 20%;
}
EDIT EDIT EDIT
<body>
<div id="header">
<!-- header is 100% width of body width-->
</div>
<div id="content">
<!-- container is 100% of body width -->
<div id="articles">
<!-- articles are 70% of container width-->
<a class="article-link-block article-1" href="#">
<img src="http://c69282.r82.cf3.rackcdn.com/361.jpg">
<div class="article-info">
Article Info need to be 20% of the height and always at the bottom
</div>
</a>
<a class="article-link-block article-2" href="#">
<img src="http://c69282.r82.cf3.rackcdn.com/361.jpg">
<div class="article-info">
Article Info need to be 20% of the height and always at the bottom
</div>
</a>
<a class="article-link-block article-3" href="#">
<img src="http://c69282.r82.cf3.rackcdn.com/361.jpg">
<div class="article-info">
Article Info need to be 20% of the height and always at the bottom
</div>
</a>
<a class="article-link-block article-4" href="#">
<img src="http://c69282.r82.cf3.rackcdn.com/361.jpg">
<div class="article-info">
Article Info need to be 20% of the height and always at the bottom
</div>
</a>
</div>
<div id="sidebar">
<!-- sidebar is 30% of container width -->
</div>
</div>
<div id="footer">
<!-- footer is 100% of body width -->
</div>
</body>
Although I believe wrapping a block-element in an
<a>is HTML5 compliant, it’s not necessary.CSS
HTML
Fiddle: http://jsfiddle.net/9dt7w/
EDIT (one picture with multiple articles). Instead of using a
<span>use a list.Fiddle for that one: http://jsfiddle.net/vtZ8g/
EDIT – Accepted Answer
http://jsfiddle.net/MXXaS/