Search code examples
csshtmllayoutelasticlayout

Fixed-width middle div and two elastic-width divs either side of it

I am trying to create an arrangement whereby there are three divs within a div that fills up 100%-width of a page. The middle div will have a fixed width and the two outer divs will take up 50% each of the remaining space. Is this achievable using CSS?

I have set up a fiddle, that doesn't work, http://jsfiddle.net/6y5hn/ with my attempt at achieving this, with the following code:

<div id="outerbox">
    <div id="leftbox">(elastic width) This should occupy all the space in the grey box to the left of the red box</div>
    <div id="centerbox">(fixed-size) should be in the center of the grey box</div>
    <div id="rightbox">(elastic width) This should occupy all the space in the grey box to the right of the red box</div>
</div>

With the CSS:

#outerbox {
    background-color:gray;
    margin-top:50px;
    width:100%;
    height:200px;
}

#centerbox {
    background-color:red;
    margin-left:auto;
    margin-right:auto;
    float:left;
    height:100px;
    width:300px;
}

#leftbox {
    background-color:yellow;
    height:300px;
    float:left;
}

#rightbox {
    background-color:pink;
    height:300px;
    float:left;
}

James

Solution

  • Not sure if this is achievable using only CSS, but here's a handy snippet of JavaScript code that can help you manage fixed and percent-based page widths more effectively:

    function resize() {
    // the more standards compliant browsers (mozilla/netscape/opera/IE7) use window.innerWidth and window.innerHeight

if (typeof window.innerWidth != 'undefined') {
    viewportwidth = window.innerWidth,
    viewportheight = window.innerHeight
}

// IE6 in standards compliant mode (i.e. with a valid doctype as the first line in the document)

else if (typeof document.documentElement != 'undefined' && typeof document.documentElement.clientWidth != 'undefined' && document.documentElement.clientWidth != 0) {
    viewportwidth = document.documentElement.clientWidth,
    viewportheight = document.documentElement.clientHeight
}

// older versions of IE

else {
    viewportwidth = document.getElementsByTagName('body')[0].clientWidth,
    viewportheight = document.getElementsByTagName('body')[0].clientHeight
}

}

    You can then call the resize() function on page load, as well as on page resize. So something like:

    <body onload="resize()">

    From here, because you have a calculated width of the page, you can resize your individual divs accordingly:

    document.getElementById("leftbox").style.width = (viewportwidth - 300)/2 + "px";
document.getElementById("rightbox").style.width = (viewportwidth - 300)/2 + "px";
document.getElementById("centerbox").style.width = 300 + "px";

    The centerbox maintains a fixed with of 300 pixels, while leftbox and rightbox have widths equal to the width of the screen minus 300 pixels, divided by two.