Design elements:

1. Image of a donauwelle from Wikimedia Commons
2. Absolute positioning: line 45 in style.css
3. Relative positioning: line 80-81 in style.css
4. Animation: lines 6-37, 52-54 in style.css
5. Link style is used in all pages.
   Two style sheets are used: style.css and print.css,
   the latter only for the print page and the former for the rest of the pages