Fix modal and panel colors in night mode
Fix modal and panel colors in night mode

Night mode provides a generally, dark interface. This fix provides the
needed CSS to also turn modal and panels into night mode design as well.
This mainly effects the help modal.

Signed-off-by: Sheogorath <1c2647ce2ee8a4ec8e5c8b1b245ca38f94844bab@shivering-isles.com>

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