Change the color mode of your OS to see the switch between the data-light-theme="light" and data-dark-theme="dark_dimmed".
Custom color variables
It's recommended to use the functional variables as much as possible. It will guarantee that the variables will work as expected with any new theme that might get added in the future. Sometimes you might still need a custom variable that changes based on the color mode. You can create a custom variable with the color-variables mixin.
The custom variables will be prefixed with --color- and can be used in the same way as other functional variables.