Sources has no component tokens of its own. Set the global tokens below under components.Sources in your token file to change them for Sources only, or pass them to ThemeScope to change one region of the page. The inline card is a Popover, so its background, shadow and padding come from the Popover tokens.
Global Tokens
The global tokens Sources reads. Set one under components.Sources to change it for Sources only, or at the top level to change every component.