CODE EXAMPLE FOR ASSEMBLY

windows detect system dark mode

RegGetValueA - gets a value from the registry (winreg.h)
use it to retrieve this key:
HKEY_CURRENT_USERSOFTWAREMicrosoftWindowsCurrentVersionThemesPersonalizeAppsUseLightTheme
res == ERROR_SUCCESS && data == 0 = dark mode
otherwise = light mode (1 is light and fallback should be light)