CSS - word-spacing not working when doing absolute positioning

I have a div and some spans inside it. I have a problem that when I use absolute positioning my word-spacing property does not work properly.

For more clearance here is the jsFiddle.

HTML:

<section id="header">
    <span>HOME</span>
    <span class="no-spacing">ABOUT US</span>
    <span>PORTFOLIO</span>
    <span class="no-spacing">CONTACT US</span>
</section>

CSS:

html, body{
    margin: 0;
    padding: 0;
    width: 100%;
    height: 100%;
}

#header {
    width: 100%;
    height: 30%;
    background-image: url(http://www.7daysinhavana.com/wordpress/wp-content/themes/7days/images/commun/back_header_global.jpg);
    font-family: 'GarageGothicBlackRegular';
    word-spacing: 20px;
    font-size: 25px;
    text-align: center;
    position: relative;
}

#header span {
    position: absolute;
    bottom: 0px;
}

.no-spacing {
    word-spacing: 0px;
}

How can I fix that error?

Any help would be highly appreciated!

Wrap your spans in a div (or other container) and position the container like:

<section id="header">
    <div>
        <span>HOME</span>
        <span class="no-spacing">ABOUT US</span>
        <span>PORTFOLIO</span>
        <span class="no-spacing">CONTACT US</span>
    </div>
</section>

CSS

#header div {
    position: absolute;
    width:100%;
    bottom: 0px;
}

jsFiddle example