MediaWiki:Citizen.css

/* All CSS here will be loaded for users of the Citizen skin */
:root {
    --transform-image-hover: none;
}

:root.skin-theme-clientpref-day,
:root.skin-theme-clientpref-night {
    --color-surface-0: var(--page-background-color);
    --color-surface-1: var(--theme-color-1);
    --color-surface-2: var(--theme-color-2);
    --color-surface-3: var(--theme-color-3);
    --color-surface-4: var(--theme-color-4);
    --color-base: var(--page-text-color);
}

:root.skin-theme-clientpref-night {
    --color-destructive__h: 360;
    --color-destructive__l: 67%;
}

h2, h3 {
    font-weight: var(--font-weight-normal);
}

.citizen-body {
    background-color: var(--color-surface-0);
    border-radius: var(--border-radius-large);
}

.citizen-body {
    padding: var(--padding-page);
}

@media screen and (min-width: 1119px) {
    #citizen-sidebar-lastmod, 
    #citizen-toc {
        background-color: var(--color-surface-0);
        border-radius: var(--border-radius-large);
        padding: calc(0.5*var(--space-unit));
    }
}

.citizen-toc .citizen-menu__heading,
.citizen-toc-contents {
    background-color: var(--color-surface-0);
}