MediaWiki:Citizen.css

/* All CSS here will be loaded for users of the Citizen skin */
:root.skin-citizen-dark {
	--color-primary__h: 41;
	--color-primary__s: 100%;
	--color-primary__l: 50%;
	
	--background-color__h: 0;
    --color-surface-0: hsl(var(--background-color__h), 0%, 5%);
    --color-surface-1: hsl(var(--background-color__h), 0%, 7%);
    --color-surface-2: hsl(var(--background-color__h), 0%, 10%);
    --color-surface-3: hsl(var(--background-color__h), 0%, 12%);
    --color-surface-4: hsl(var(--background-color__h), 0%, 15%);
    --background-color-primary--hover: hsl(var(--background-color__h), 0%, 15%);
    --background-color-primary--active: hsl(var(--background-color__h), 0%, 20%);
    --background-color-overlay: hsla(var(--background-color__h), 0%, 10%, 0.95);
    --background-color-overlay--lighter: hsla(var(--background-color__h), 0%, 10%, 0.6);
}

.skin-citizen-dark #siteSub {
	display: none;
}

.skin-citizen-dark .citizen-menu > li > a {
	color: var(--color-surface-0);
}