How can I create this complicated layout using only CSS?

Question

OVERVIEW

I've read a bunch of the "vertical-centering with CSS" tutorials out there:

• http://emergentweb.com/test/valign.html
• http://blog.themeforest.net/tutorials/vertical-centering-with-css/
• http://www.jakpsatweb.cz/css/css-vertical-center-solution.html
• http://www.alistapart.com/d/footers/footer_variation1.html
• http://phrogz.net/css/vertical-align/index.html

... but there is another component to my layout that is not represented in any of these methods in addition to the vertical centering.

.

There are 2 components to this layout. First, vertically & horizontally centering the content between the header and footer (which is a sticky footer). I have the code in a fiddle to demonstrate but I haven't been able to get this to work in IE (the code is at the bottom of the post).

• http://jsfiddle.net/UnsungHero97/yZPwu/4/embedded/result/

The second component is where the green arrow is pointing. That represents a hidden element which is meant to expand vertically downwards when clicking on some of the text. However, I DO NOT WANT this expansion to move the content upward as if everything was being centered... I want this element to expand downwards without affecting the position of the content AND pushing the sticky footer down as it expands. In most cases, a browser scrollbar will appear.

So the effect of the hidden element expanding should be like a banner falling off an edge.

This is what the layout should look like after the hidden element has been expanded:

---

QUESTION

So how would I achieve this layout using only CSS and have it be cross-browser compatible Please let me know if I need to explain further to clarify confusion.

---

CODE SO FAR

Note... I have left out some of the boilerplate code that comes with HTML5 BoilerPlate.

CSS

/* --------------------------------------------------------------------------
   General Layout
   -------------------------------------------------------------------------- */
html,body {
    height: 100%;
}

body {
    background-color: #e3e3e3;
    color: #696969;
}

#wrapper {
    min-height: 100%;
    width: 100%;
    min-width: 936px;
}

/* --------------------------------------------------------------------------
   Header
   -------------------------------------------------------------------------- */
header {
    background-color: #232323;
    height: 108px;
    width: 100%;
    margin: auto;
    padding: 24px 0px 8px 0px;
    position: relative;
}

#header-content {
    height: 100%;
    width: 800px;
    margin: auto;
    position: relative;
}

/* --------------------------------------------------------------------------
   Footer
   -------------------------------------------------------------------------- */
footer {
    background-color: #dbdbdb;
    border-top: 1px solid #bababa;
    height: 30px;
    width: 100%;
    min-width: 936px;
    margin-top: -32px;
    position: relative;
}

#footer-content {
    border-top: 1px solid #f8f8f8;
    height: 100%;
    margin: 0px auto;
    position: relative;
}

#footer-content > div {
    width: 800px;
    margin: 0px auto;
}


/* --------------------------------------------------------------------------
   DOWNLOADZONE
   -------------------------------------------------------------------------- */
#dl-info {
    width: 400px;
    margin: auto;
    display: table-cell !important;
    vertical-align: middle;
}

#show-hide {
    margin: 8px 0px;
    text-align: center;
}

/* --------------------------------------------------------------------------
   General helper classes
   -------------------------------------------------------------------------- */
.zone {
    background: none;
    border: 0px none;
    height: 100%;
    min-height: 100px;
    width: 100%;
    padding-top: 140px;
    padding-bottom: 31px;
    display: table;
    position: absolute;
    top: 0px;
    bottom: 0px;
    overflow: hidden;
}

.border {
    border: 1px solid #454545;
}

.clear {
    clear: both;
}


/* Hide from both screenreaders and browsers: h5bp.com/u */
.hidden { 
    display: none !important;
    visibility: hidden;
}

/* Hide only visually, but have it available for screenreaders: h5bp.com/v */
.visuallyhidden { 
    border: 0;
    clip: rect(0 0 0 0);
    height: 1px;
    margin: -1px;
    overflow: hidden;
    padding: 0;
    position: absolute;
    width: 1px;
}

/* Extends the .visuallyhidden class to allow the element to be focusable when navigated to via the keyboard: h5bp.com/p */
.visuallyhidden.focusable:active, 
.visuallyhidden.focusable:focus { 
    clip: auto;
    height: auto;
    margin: 0;
    overflow: visible;
    position: static;
    width: auto;
}

/* Hide visually and from screenreaders, but maintain layout */
.invisible { visibility: hidden; }

/* Contain floats: h5bp.com/q */
.clearfix:before, 
.clearfix:after { 
    content: "";
    display: table;
}

.clearfix:after { clear: both; }

.clearfix { *zoom: 1; }

​ HTML

<!doctype html>
<!-- paulirish.com/2008/conditional-stylesheets-vs-css-hacks-answer-neither/ -->
<!-- misteroneill.com/improved-internet-explorer-targeting-through-body-classes/ -->
<!--[if lt IE 7]> <html class="no-js ie ie6 lt-ie9 lt-ie8 lt-ie7" lang="en"> <![endif]-->
<!--[if IE 7]> <html class="no-js ie ie7 lt-ie9 lt-ie8 lt-ie7" lang="en"> <![endif]-->
<!--[if IE 8]> <html class="no-js ie ie8 lt-ie9 lt-ie8" lang="en"> <![endif]-->
<!--[if IE 9]> <html class="no-js ie ie9 lt-ie9" lang="en"> <![endif]-->
<!--[if (gte IE 9)|!(IE)]>
<!-->
<html class="no-js" lang="en">
<!--<![endif]-->
<head>
    <title>Layout</title>
</head>

<body class="select-none">

    <div id="wrapper">

        <header>
            <div id="header-content">
            </div><!-- end #header-content -->
        </header><!-- end header -->

        <div id="downloadzone" class="zone clearfix">

            <div id="dl-info">
                <div class="border">
                    <div id="dl-button">Icon Here</div>
                    <div id="dl-extras">
                        <div id="dl-filename">text text text</div>
                        <div id="show-hide">CLICK TO SHOW/HIDE HIDDEN ELEMENT</div>
                    </div>
                </div>
            </div>

        </div><!-- end #downloadzone -->

    </div><!-- end #wrapper -->

    <footer>
        <div id="footer-content">
            <div class="border-highlight">
            </div><!-- end .border-highlight -->
        </div><!-- end #footer-content -->
    </footer><!-- end footer -->

</body>
</html>
​

Answer 1

If I understand you correctly (my apologies if I'm answering the wrong question here), you want an element of unknown height to be horizontally and vertically centered, with a possible other element beneath it that shouldn't affect the position when it's displayed?

How about using overflow? Here's a demo. I'll put the code here soon.

Compatibility warning: the vertical centering method used will not work in Internet Explorer 7 or lower.