title: Parallax.js moves my css-positioned elements
body: <p>I'm starting out experimenting with Parallax.js and having a problem:</p>
  
  <p>I lay out some clouds in the sky, and position their 'top' position using CSS in such a way that they're distributed over the sky (I've also tried this using Javascript and Greensock GSAP, in this case setting their 'y').  However init'ing Parallax.js just wipes their positions clear and sets them all on top of each other.  </p>
  
  <p>I've gone through the config variables in Parallax.js and tried changing some, but it doesn't help.'</p>
  
  <p>What am I not understanding?</p>
  
  <p>Also, is it possible to animate Parallax.js positioned elements using GSAP?  That is, have them move across the screen as well as being affected by Parallax.ja?</p>