Bysen:If dark/styles.css

/* this should be the fallback */
.ifdark > .dark {
    display: none;
}
.ifdark > .nodark {
    display: inherit; /* fallback */
    display: initial;
}

html.skin-theme-clientpref-night .ifdark > .nodark {
    display: none;
}
html.skin-theme-clientpref-night .ifdark > .dark {
    display: inherit; /* fallback */
    display: initial;
}

/* dark mode gadget */
html.client-dark-mode .ifdark > .nodark {
	display: none;
}

html.client-dark-mode .ifdark > .dark {
    display: inherit; /* fallback */
    display: initial;
}

@media screen and (prefers-color-scheme: dark) {
	html.skin-theme-clientpref-os .ifdark > .nodark {
	    display: none;
	}
	html.skin-theme-clientpref-os .ifdark > .dark {
	    display: inherit; /* fallback */
	    display: initial;
	}
}

@media screen and (prefers-color-scheme: light) {
	html.skin-theme-clientpref-os .ifdark > .dark {
	    display: none;
	}
	html.skin-theme-clientpref-os .ifdark > .nodark {
	    display: inherit; /* fallback */
	    display: initial;
	}	

}