Question 1

Why is my shadow invisible in dark mode?

Accepted Answer

A black shadow disappears on a dark surface. In dark themes elevation is usually conveyed by lightening the surface or adding a subtle light border instead.

Question 2

One shadow or layered shadows?

Accepted Answer

Layered looks more real: a short dark shadow grounds the object while a wide soft one mimics ambient light. A single large blur usually reads as artificial.

Box Shadow Generator