Image overlay on responsive sized images bootstrap

Question

I am trying to create a responsive grid of images (with descriptions) that when moused over will have a color overlay (just the image and not the text). Because of the responsive heights of the images, I am having an issue where the overlay covers everything and not just the image.

Any way I can fix this?

I've recreated the issue here for easier understanding: http://jsfiddle.net/r8rFc/

Here is my HTML:

<div class="row">

    <div class="col-xs-12 col-sm-6 col-md-3 project">
        <a href="#">
            <div>
                <img src="http://placehold.it/500x500" class="img-responsive"/>
                <div class="fa fa-plus project-overlay"></div>
            </div>
            <div style="text-align:center;">
                <h3>Project name</h3>
                <p>Image description</p>
            </div>
        </a>
    </div>

</div>

And my CSS:

.project-overlay {
    position: absolute;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(41,128,185,0.9);
    color: #fff;
    padding: 50%;
}

Thanks in advance!

Answer 1

Add a class to the containing div, then set the following css on it:

.img-overlay {
    position: relative;
    max-width: 500px; //whatever your max-width should be 
}

position: relative is required on a parent element of children with position: absolute for the children to be positioned in relation to that parent.

DEMO

Answer 2

When you specify position:absolute it positions itself to the next-highest element with position:relative. In this case, that's the .project div.

If you give the image's immediate parent div a style of position:relative, the overlay will key to that instead of the div which includes the text. For example: http://jsfiddle.net/7gYUU/1/

 <div class="parent">
    <img src="http://placehold.it/500x500" class="img-responsive"/>
    <div class="fa fa-plus project-overlay"></div>
 </div>

.parent {
   position: relative;
}