It's hard to tell what is the context here exactly - German isn't my strongest language, but i think Card UI Patterns can be used effectively to present a vast variety of content.
However, I think the issue here is excessive use of drop shadow on elements and poor use of typographic color, contrast and font size - everything seems to jump out and fight for attention.
If elements in the middle under "Zuletzt.." are also navigation i could imagine it is a bit odd placement and might not be easy to use if the whole page is a scrollable container.
I would suggest to sit down with your design and go over specific UI elements, review information they deliver, function they serve and how important those are to the end user. And then make necessary changes to typography to create more contrast by highlighting some parts and pushing less important information to the background.
To tame use of drop shadows maybe it is worth looking at something like Material UI and see how they use different elevation to place UI elements higher or lover on the UI. Generally a good resource with clear outlined design principles.
Hope this helps, good luck!