I feel a bit like a moron. So I ask for your help.

Please look here:
www.joomlage.com/demos/joomlage_0118/index.php
When you click on a menu item, e.g. "Layouts", the article appears directly beneath the header block. This means that the backgroud photo is covered by the article.
In my setup the article is in the bottom part: to see it one has to scroll down or click on the center "down-arrow" ("v"). Obviously, my articles are in the bottom / base / footer posiiton.
(my website:
albin25.eu )
Where may I control this?
Sorry for the beginner's question.

BR Ghaffy