1) Basically, the navigation is structured in such a way that persons with visual disturbances (also colour vision disturbances) receive support in every level.
It meets at least the requirements of conformity level WCAG2.0 AA, which is the legal requirement for the federal government.
2) The DLN contains 'pages items' (without arrow) and 'menu categories' (with arrow to the right).
If you click on a 'menu category', a new 'tile' opens to the right!
Clicking on a 'page item' opens the corresponding page. The DLN closes.
3) Each 'tile' or category has an 'overview page'. Since this does not open when you click on a menu category (but the corresponding 'tile' opens), there is an automatically generated menu entry (if necessary freely nameable by the editor) at the beginning of each 'tile'. The page 'Overview/Übersicht' have in this case the following URL: http://www.domain.ch/Themen/
4) The DLN covers the entire viewport. If contents run out of a 'tile', the 'tile' can be scrolled. Arrows (bottom/top) also appear instead of a scroll bar, which can be used to scroll with hover+click.
The DLN consists of following organisms:
DLN-StartDLN-TileDLN-Tile (last-of-type)