title: Background-image behind Carousel
body: <p>I have a Bootstrap carousel working fine, but I want to add a background image <em>behind</em> this carousel, the background image at width 100 %, and inside the image, covering 80% of the image, having the carousel working. 
  I've tried having background-image in my #homecarousel's CSS, I've tried some tricky position:absolute manipulations (which are not a good idea anyway), I've checked the already existing posts around, but nothing works…
  Basically it's just a small rectange inside a big rectangle, and the small rectangle is a carousel…
  Any idea ?
  I would prefer a pure CSS solution to a Javascript manipulation, because I didn't program 90% of the site, just taking it now and it's all a mess of files so I would prefer touching as few as I can.
  Many thanks </p>