Layout collaps when integration visual lightbox

I wonder if you could help me out with I guess is just a css code problem, let me explain and add the links so you can see my pages and understand the problem.
Here’s the link to the index page where I try to use the ordinary lightbox, but I wanted to style the images and got in conflict with the css code belonging to the images on the page (fix not lightbox). The lightbox works though.
http://www.educaresavanzar.org/test/index.html
Here’s the link with your visual lightbox pasted into the page layout, the lightbox works, but my original layout collapse, see menu bar underneath the gallery and the top box on the right!!
http://www.educaresavanzar.org/test/galerie.html
Here’s the link to the visual lightbox page on a individual page without incorporating it into my webpage, works fine!
http://www.educaresavanzar.org/test/gallery.html
One more question I did enabled the watermark in order not to show the link, somehow it stil shows in the slideshow!
I thank you very much in advance for your help, I think it’s a minor problem, but I can’t find the bug, I appreciate very much your advice.
My best regards.
Nathalie