https://www.mintpressnews.com/wp-content/themes/core/js/dark-mode.js?ver=16b9d6cb6fe00987

1/**
2 * Handle dark-mode toggle in the header.
3 *
4 * Loaded in a separate JS file, so we can prevent FOIT (flash of incorrect theme).
5 */
6
7const prefersDarkScheme = window.matchMedia( '(prefers-color-scheme: dark)' );
8const currentTheme = localStorage.getItem( 'dark-mode-theme' );
9
10if ( ( ! currentTheme && prefersDarkScheme ) || 'dark' === currentTheme ) {
11	document.body.classList.add( 'dark-theme' );
12}
13
14jQuery( function() {
15	const btn = document.querySelector( '[data-js="lipe/project/template-parts/header/social/dark-mode"]' );
16	btn.addEventListener( 'click', function() {
17		document.body.classList.toggle( 'dark-theme' );
18		let theme = 'light';
19		if ( document.body.classList.contains( 'dark-theme' ) ) {
20			theme = 'dark';
21		}
22		localStorage.setItem( 'dark-mode-theme', theme );
23	} );
24} );