Make child visible outside an overflow:hidden parent

You can use the clearfix to do "layout preserving" the same way overflow: hidden does.

.clearfix:before,
.clearfix:after {
    content: ".";    
    display: block;    
    height: 0;    
    overflow: hidden; 
}
.clearfix:after { clear: both; }
.clearfix { zoom: 1; } /* IE < 8 */

add class="clearfix" class to the parent, and remove overflow: hidden;

Neither of the posted answers worked for me. Setting position: absolute for the child element did work however.

This is an old question but encountered it myself.

I have semi-solutions that work situational for the former question("Children visible in overflow:hidden parent")

If the parent div does not need to be position:relative, simply set the children styles to visibility:visible.

If the parent div does need to be position:relative, the only way possible I found to show the children was position:fixed. This worked for me in my situation luckily enough but I would imagine it wouldn't work in others.

Here is a crappy example just post into a html file to view.

<div style="background: #ff00ff; overflow: hidden; width: 500px; height: 500px; position: relative;">
    <div style="background: #ff0000;position: fixed; top: 10px; left: 10px;">asd
        <div style="background: #00ffff; width: 200px; overflow: visible; position: absolute; visibility: visible; clear:both; height: 1000px; top: 100px; left: 10px;"> a</div>
    </div>
</div>