Vertical Centering some Text over an Image with Dynamic Height - html

Question

For whatever reason I am really beating myself up with this... No doubt because of the lack of support for a real "proper" way of vertically centering anything.
The Goal:
Is to have a set of four images, each inside their own responsive columns. Each image has a white overlay, that when hovered reveals more of the image, as well as a title for each of the 4 images that is horizontally and vertically centered inside the image.
I could easily achieve this if I set specific width/heights and stuck the image inside CSS rather than the HTML. For SEO reasons I want the image to be present in the HTML.
Additionally because of the responsive nature, the images must scale to 100% of the width of the column they reside in. Consequently, because the width scales, the height scales as well.
So the first issue is getting the "caption" as I am calling it in my classes, to appear over the top of the image. Easily done with a simple position: absolute; as well as top: 0; and left: 0; on the caption and position: relative; on the container.
The big problem and second issue, is vertically centering the "Gallery 1" text over the top of the image. I have to use the position: absolute; bit as I mentioned above just to get the text over-top of the image. From there I can't manage to get a display: table; solution to work, nor a -50% margin solution to work.
Here is a JS Fiddle
My HTML:
<div class="container">
<img src="http://lorempixel.com/output/city-q-c-640-480-8.jpg" />
<div class="caption">
Gallery 1
</div>
</div>
Any ideas on how to achieve this? I would like to stay at least IE8 supported, and I am using selectivizr already, so pseudo-classes don't bother me.

Answer 1

First, I wasn't sure about what you mean exactly. But as you mentioned:
The issue is centering the text Gallery 1 vertically over the top of the image. Centering it horizontally is easy with a simple text-align but centering it vertically is what is eluding me.
Here is my attempt to align the text vertically over the image. Actually the concept comes from this approach of a similar topic on SO:
.container { position: relative; }
.container img {
vertical-align: bottom; /* Remove the gap at the bottom of inline image */
max-width: 100%;
}
.caption {
position: absolute;
top: 0;
bottom: 0;
left: 0;
right: 0;
font: 0/0 a; /* Remove the gap between inline(-block) elements */
}
.caption:before {
content: ' ';
display: inline-block;
height: 100%;
vertical-align: middle;
}
.caption a {
font: 16px/1 Arial, sans-serif; /* Reset the font property */
display: inline-block;
vertical-align: middle;
text-align:center;
background: rgba(255, 255, 255, 0.75);
width: 100%;
padding: 1% 0; /* Added a relative padding for the demo */
}
WORKING DEMO.
This relies on CSS2.1 and it will definitely work on IE8+ (excluding rgba()).

Answer 2

If I understand your issue correctly, this may work for you:
Working Demo
If you need the image to scale when hovered over, then simply adding a :hover on the container and changing it's width should work.
CSS:
.container {
// existing styles
-webkit-transition: all .2s; // needs prefixes for other browsers.
}
.container:hover {
width: 500px;
}
The only issue is that transition has no support for IE9 or earlier. So you'd need to go a JS route if that is an issue.