--background-color-dp-XX is now fully deprecated in favor of a simpler 4 color surface system. It can be accessed through the --color-surface-X CSS var.
* Looks more natural
* Can be customized through the surface-shadow and shadow-strength CSS var
* Light mode and dark mode have been different shadow now, it should be more visible in dark mode
* Box-shadow is a CSS var, which can be used in templates and wiki CSS