The blue image of some droplets needs to be within the right hand panel. At the moment it is staying in the same place and not moving if the browser window is resized, like the rest of the page.
I have put the tag inside the main container tag but this isn't helping. Where am I going wrong?
The reason it is staying in the same place is because you have used absolute positioning for the image. There are a couple of ways to solve this, but it all comes down to using a relative position and floating the droplet image.