CSS-only: How can I center fixed width div between two divs that fill the remaining space?

Question

JSFIDDLE

EDIT: Trying to achieve the opposite of this.
_{(instead of 2 fixed-width divs on the sides and one fluid-width div in the middle,
I'm trying to get 2 fluid-width divs on the sides and one div centered in the middle)}

I have 3 divs: A, B, and C.

B needs to sit centered between A and C.

What I'm currently doing is pretty much matching what's going on above. But, if A, B, and C's container has an odd width, some browsers are rounding A and C's widths down and others up (leaving C 1px too long and 1px too short, respectively).

_{notice the extra pixel to the right of C}

_{notice the space to the right of C is a pixel thinner.}

I don't care how many nested divs I need, but I've been spending way too much time on this! If someone already has a sure-fire solution to this problem, please share!

notes:
- A, B, and C's parent can't have overflow hidden.
- A, B, and C can't overlap (they have translucent png's)

This is my starting point: JSFIDDLE

Answer 1

Here are two ways that work, both with caveats (warning, both require a wrapper):

HTML

<section class="wrapper">
    <div class="column" id="a"></div>
    <div class="column" id="b"></div>
    <div class="column" id="c"></div>
</section>​​​​​​​​​​​

Base CSS

.column {
    height: 3em;
}

#a {
 background-color: red;   
}
#b {
 background-color: green;
}
#c {
 background-color: blue;   
}

#b {
  width: 50px;   
}

CSS3 Approach:

.wrapper {
    display:box;
    box-orient:horizontal;
    box-align:stretch;    
}

#a, #b {
    box-flex:1.0;
}

Caveat: Only supported (so far) in Firefox and Webkit (Chrome/Safari), both requiring prefixed rules. The above is what it will be someday.

Here is a demo with prefixes: http://jsfiddle.net/crazytonyi/cBVTE/

Table-Display approach

.wrapper {
    display: table;
    width: 100%;
    table-layout: fixed;

}    
.column {
    display: table-cell;
}

Caveats: IE didn't start supporting this display type until 7 or 8. On the other hand, worrying about users on older versions of IE is like worrying about people who still turn off cookies and javascript. Either they catch up or get used to pages breaking. End the pandering!

Here's a demo using the above: http://jsfiddle.net/crazytonyi/kM46h/

In both cases, no floats or positioning needed, just willingness to give the middle finger to older browsers. How old depends on which method you choose.

Answer 2

EDIT: Please use Anthony's solution! It meets all of the requirements without any terribly hacky CSS! If you do need to support older browsers, feel free to use my solution (but, srrsly, Anthony's solution is perfect for most cases).

---

I don't know how I haven't tried this solution yet, but this seems to work even better than this question's accepted answer! No rounding!

solved!

If we think of the rounded 50% as a value (X) and constant width of B as value Y, then we need:

width of A = X
width of C = 100% - X

I decided to use this as my structure:

<container>
  <a></a>
  <b></b>
  <c_holder>
    <c>
    </c>
  </c_holder>
</container>

Q. How can we get C to have a width of container_width - X?
A. We give C a container called c_holder with width 100% and give C a left offset of X (50%).

forget B for now...

now we have 2 divs next to eachother... each roughly 50% but adding up to exactly 100%.

Throw all of these into a container, and give this container a margin-right of Y (the width of the B div). now we have A and C next to eachother, but taking up 100% - Y of the width.

give c_holder a left offset of Y and drop B in between A and c_holder. apply a left float on A and B.

now A's width is X, B's width is Y, C's total left offset is X + Y, and C's visible width is 100% of the container - X - Y.

kinda funky, but it's worked perfectly in IE7, Chrome, and Safari. I'll test FF later.

Answer 3

i think you have to use like this..

HTML

<div class="a">a</div>
<div class="b">b</div>
<div class="c">c</div>

CSS

.a
{
width:50%;
height:25px;
background-color:#0F0;
float:left  
}
.b
{
width:13px;
height:25px;
background-color:#FFF;
margin-left:-6px;
float:left; 
position:relative;
z-index:99;
}
.c
{
width:50%;
height:25px;
background-color:#C33;
margin-left:-7px;
float:left; 
}
</style>

Answer 4

<style>

.a{ width:50%; height:25px; background-color:#0F0; float:left }
.b{ width:13px; height:25px; background-color:#FFF; float:left;
    position:relative; left:51%;}
.c{ width:50%; height:25px; background-color:#C33; float:right; }

</style>

Answer 5

demo on dabblet.com:

http://img838.imageshack.us/img838/6116/cff430b799254087b6ec991.png

html:

<div id="main">
    <div class="half left">
        <div>
            <div id="a" class="col"> </div>
         </div>
    </div>
    <div class="half right">
        <div>
            <div id="c" class="col"> </div>
         </div>
    </div>
    <div id="b" class="col"> </div>
</div>

css:

#main {
    height: 40px;
    width: auto;
    border: 1px solid #cfcfcf;
    position: relative;
}

.half {
    width: 50%;
    height: 100%;
    position: absolute;
    top: 0;
}

.half.left { left: 0; }
.half.right { right: 0; }

.half > div {
    height: 100%;
    padding:0 8px;
}

.half.left > div { padding-left: 7px; }
.half.right > div { padding-right: 7px; }

.col {
    height: 100%;
    margin-top: 3px;
}

#a,
#c {
    background-color: green;
}

#b {
    background-color: red;
    margin-left: auto;
    margin-right: auto;
    width: 14px;
}

update: updated with no overlaping