How to fill the gap while scale

Question

How can fill the gap at the bottom while using -webkit-transform:?

There is a gap when div becoming small. How can I fix this gap?

Here is the code

<div id="popUp">
    <div id="trans">
        <h1>hover me</h1>
    </div>
    <p>Mauris mauris ante, blandit et, ultrices a, suscipit eget, quam. Integer ut neque. Vivamus nisi metus, molestie vel, gravida in, condimentum sit amet, nunc. Nam a nibh. Donec suscipit eros. Nam mi. Proin viverra leo ut odio. Curabitur malesuada. Vestibulum a velit eu ante scelerisque vulputate</p>
</div>

CSS

#popUp{
    height: auto;
    width:400px;
    background: #EEE;    
}
#trans{
    width:100%;
    height:200px;
    background: yellow;

    -moz-transition: all 0.5s;
    -o-transition: all 0.5s;
    -webkit-transition: all 0.5s;
    transition: all 0.5s;

    -webkit-transform-origin: left top 0;
       -moz-transform-origin: left top 0;
         -o-transform-origin: left top 0;
        -ms-transform-origin: left top 0;
            transform-origin: left top 0;
}
#trans:hover{
    -moz-transform: scale(.5);
    -ms-transform: scale(.5);
    -o-transform: scale(.5);
    -webkit-transform: scale(.5);
    transform: scale(.5)
}
h1{
    text-align: center;
}

Demo: http://jsfiddle.net/sweetmaanu/XpJEQ/3/

I couldn't find a proper solution.

Answer 1

The only solution I can think of would be to remove the element from the DOM flow (set it's parent to position: relative, then absolutely position the element) and animate the padding-top of the subsequent element.

Demo: http://jsfiddle.net/XpJEQ/7/

CSS (minus vendor prefixes):

#popUp {
    background: #EEE;
    position: relative;
    width: 400px;
    max-height: 300px;
}
#trans {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 200px;
    background: yellow;
    transition: all 0.5s;
    transform-origin: left top 0;
}
#trans:hover { transform: scale(.5); }
#trans + * {
    padding-top: 210px;
    transition: all 0.5s;
}
#trans:hover + * { padding-top: 110px; }
h1 { text-align: center; }

HTML:

<div id="popUp">
    <div id="trans">
        <h1>hover me</h1>
    </div>
    <p>Mauris mauris ante, blandit et, ultrices a, suscipit eget, quam. Integer ut neque. Vivamus nisi metus, molestie vel, gravida in, condimentum sit amet, nunc. Nam a nibh. Donec suscipit eros. Nam mi. Proin viverra leo ut odio. Curabitur malesuada. Vestibulum a velit eu ante scelerisque vulputate</p>
</div>