Vertically center rotated text with CSS

I have the following HTML:

<div class="outer">
    <div class="inner rotate">Centered?</div>
</div>

div.outer is a narrow vertical strip. div.inner is rotated 90 degrees. I would like the text "Centered?" to appear centered in its container div. I do not know the size of either div in advance.

This comes close: http://jsfiddle.net/CCMyf/2/. You can see from the jsfiddle that the text is vertically centered before the transform: rotate(-90deg) style is applied, but is somewhat offset after. This is particularly noticeable when div.outer is short.

Is it possible to center this text vertically without knowing any of the sizes in advance? I haven't found any values of transform-origin that solve this problem.

Solution 1:

The key is to set position top and left to 50% and then transformX and transformY to -50%.

.inner {
    position: absolute;
    top: 50%;
    left: 50%;
}

.rotate {  
    transform:  translateX(-50%) translateY(-50%) rotate(-90deg);
}

see: http://jsfiddle.net/CCMyf/79/

Solution 2:

It may be a bit late for answering that question, but I stumbled on the same issue and found some way of achieving it, by adding another div in the way.

<div class="outer">
    <div class='middle'><span class="inner rotate">Centered?</span></div>
</div>

and applying a text-align: center on that middle element, along with some positioning stuff:

.middle {
    margin-left: -200px;
    width: 400px;
    text-align: center;
    position: relative;
    left: 7px;
    top: 50%;
    line-height: 37px;
}

The .inner also gets a display: inline-block; to enable both rotate and text-align properties.

Here is the corresponding fiddle : http://jsfiddle.net/CCMyf/47/