assets/css/_feather-custom.scss

@media (prefers-color-scheme: dark) {
  // very basic support for dark mode until Feather supports this natively
  :root {
    --tw-color-text-primary: var(--tw-color-gray-0);
  }
  .Button {
    --feather-button-background-color: var(--tw-color-gray-1100);
    --feather-button-background-color-hover: var(--tw-color-gray-900);
    --feather-button-border-color: var(--tw-color-gray-700);

    --feather-button-primary-background-color-active: var(--tw-color-gray-200);
    --feather-button-primary-background-color: var(--tw-color-gray-0);
    --feather-button-primary-background-color-hover: var(--tw-color-gray-100);
    --feather-button-primary-color: var(--tw-color-gray-1100);
  }
}