Ground slab on a gentle slope for a single-family house with a basement

Hello everyone
I want to build a single-family house without a basement. Planned structure:
-gravel, compacted. Slope evened out with topsoil and gravel.
-Styrodur (full thermal insulation)
-25 cm ground slab (without strip foundations)

The house will be built on a slight slope. Slope across the house width (10 m) approx. 90 cm, whereby the first half of the house will stand on a flat section, and the slope begins in the second half.
I have a bad feeling about the ground slab. Can the compacted gravel eventually give way so that the ground/gravel under the house "floats away"? Or is compacted gravel sufficient/OK? Should strip foundations perhaps be used instead, or are there other ideas?

Please share your opinions, possibly a suggestion on how this could be better executed. Thank you very much

Regards

Topsoil is completely unsuitable for your project. The thickness of the base slab results from structural requirements and not from an owner's idea. The thickness of the insulation is based on the specifications of the thermal protection certificate. The correct and strongly recommended procedure would be a soil survey including foundation recommendation and the structural analysis based on it.

Yep, structural engineers and geotechnical experts specify how the construction/substructure is done so that nothing "washes away." You or anyone here in the forum don’t need to worry about that...

What some people here want to make up for themselves is really unbelievable?!

Rising prices may lead to increasing happiness knight-errantry?

But when it comes to the building application, reality catches up at the latest.

Please, anyone who has ideas and suggestions I would be grateful, but those who only want to explain jokes and nonsense should rather remain silent. Of course, everything will go through a structural engineer, but my question was intended to gather ideas from experienced builders.