comment faire de la div de l'image d'arrière-plan sensible

Comment faire de cette image sensible

HTML:

<section id="first" class="story" data-speed="8" data-type="background">
    <div class="smashinglogo" id="welcomeimg" data-type="sprite" data-offsetY="100" data-Xposition="50%" data-speed="-2"></div>
</section>

CSS:

#first .smashinglogo {background: url(../images/logo1.png)  50% 100px no-repeat fixed;}

OriginalL'auteur User1038 | 2014-02-25