Safari Technology Preview now supports dark mode via `@media (prefers-color-scheme: dark)` in CSS media queries. 

Same should be supported in Electron apps to enable automatic light/dark mode switching.

shell/browser/atom_browser_client.cc
switches::kPreloadScripts,
          base::JoinString(preloads, kPathDelimiter));
    if (CanUseCustomSiteInstance()) {
      command_line->AppendSwitch(
          switches::kDisableElectronSiteInstanceOverrides);
    }
  }
}
void AtomBrowserClient::AdjustUtilityServiceProcessCommandLine(
    const service_manager::Identity& identity,
    base::CommandLine* command_line) {
#if defined(OS_MACOSX)
  if (identity.name() == video_capture::mojom::kServiceName ||
      identity.name() == audio::mojom::kServiceName)
    command_line->AppendSwitch(::switches::kMessageLoopTypeUi);
#endif
}
void AtomBrowserClient::DidCreatePpapiPlugin(content::BrowserPpapiHost* host) {
#if BUILDFLAG(ENABLE_PEPPER_FLASH)
  host->GetPpapiHost()->AddHostFactoryFilter(
      base::WrapUnique(new ChromeBrowserPepperHostFactory(host)));
#endif
}
std::string AtomBrowserClient::GetGeolocationApiKey() {
  std::unique_ptr<base::Environment> env(base::Environment::Create());
  std::string api_key;
  env->GetVar("GOOGLE_API_KEY", &api_key);
  return api_key;
}
scoped_refptr<content::QuotaPermissionContext>