Closes#29731
tl;dr nicer, softer shadows, some refinement on elevated backgrounds
Comparison for various seeds (old on top, refined on the bottom):
Dark mode:
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## Summary by CodeRabbit
## Summary by CodeRabbit
- **Style**
- Fine-tuned the color calculations in both dark and light mode themes
to enhance visuals of elevated levels.
- Adjusted the `Elevation` test story for better evaluation.
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