hugo-theme-paradox/layouts/partials/color-switcher.html

<div class="color-switcher">
	<div class="js-toggle-wrapper">
		<div class="js-toggle" style="display: none">
			<div class="js-toggle-track">
				<div class="js-toggle-track-check">
					<img
						src="data:image/png;base64,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"
						role="presentation" style="pointer-events: none;" width="16" height="16">
				</div>
				<div class="js-toggle-track-x">
					<img
						src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAACAAAAAgCAYAAABzenr0AAAAAXNSR0IArs4c6QAAAAlwSFlzAAALEwAACxMBAJqcGAAAAVlpVFh0WE1MOmNvbS5hZG9iZS54bXAAAAAAADx4OnhtcG1ldGEgeG1sbnM6eD0iYWRvYmU6bnM6bWV0YS8iIHg6eG1wdGs9IlhNUCBDb3JlIDUuNC4wIj4KICAgPHJkZjpSREYgeG1sbnM6cmRmPSJodHRwOi8vd3d3LnczLm9yZy8xOTk5LzAyLzIyLXJkZi1zeW50YXgtbnMjIj4KICAgICAgPHJkZjpEZXNjcmlwdGlvbiByZGY6YWJvdXQ9IiIKICAgICAgICAgICAgeG1sbnM6dGlmZj0iaHR0cDovL25zLmFkb2JlLmNvbS90aWZmLzEuMC8iPgogICAgICAgICA8dGlmZjpPcmllbnRhdGlvbj4xPC90aWZmOk9yaWVudGF0aW9uPgogICAgICA8L3JkZjpEZXNjcmlwdGlvbj4KICAgPC9yZGY6UkRGPgo8L3g6eG1wbWV0YT4KTMInWQAABwNJREFUWAmtV1tsFFUY/s6Z2d22zLYlZakUCRVaQcqlWIiCiS1gTEB9UAO+GR9En3iQGI0xJiSiRB98MjEq8cEQTSBeHhQM0V7whtEGDWC90BYitxahtNtu25058/v/ZzvLbilawJNM5+yZ89+//1LgJhYRNLW1uDfBAvpGiIk2O5auvfFxqIH3ZJ8/u06GN6Z9+wVl5SjcD1IbZa/UPkPyYl2uR4dreoD2bnbYxTlBBRytkHXtAREphP5KuH4lddx9h70yxX05t7yYXwGb6W8nx1jibpl2rFlGBxcG9M18okOrn7Bnk/BAO/4bI0UeEE1zjBp3UmvjOxJXJdaKN/ZiIu4tOZrAb4aTdZAZArKmWeiiJZ6jt5tiagdCS9+6cgO1Ne6Mvhe+ixTIfyDVhipnK9p+P0Edqx9RW/YZtQVGmOLChRxNNlyPsTEgPQKMB3dbEHa0h1awYmQ83enTd2vmUtvKd1Glv2RkzBb+kZGRrKtjzG60Wguhd/lJZBingbcfWWe72vjT75bJDrhYtvA0hrurETDr5HyF2Knb1MM4ab//xIoOqueA0edRnkkinTyJdYvqLFDZO4zUPFCvVoDjJq4T7TE61IWh4x5KqxX5KVKkX8WZ/t2ov2cb3MHt4dhIyOxIJxJOOF6xRx/99BksXLoecWcXytILMNBDqKpnGZWPquYfPxY8iXGR9fK+SgFrgcRPXPjVqhehL+3EmZ5RGJQi1QBU8TPThQnOQzm+5UXGIcetUeEAfP13VwzpI+w1jGJWdSliNfvVhiMPiOsllJag4M/UGHiqM6dlBb2OTLKHHV6KkvogrJ4XhBWniWK/Gp1MQyf93FOeUXKmKk/FzJxbQtKLjFXYT4USupy8fQVir2ynVEBiZMG0qtOHMS/AW4Gwrk7BG3C1F0B5nqNKE0CME4MfVRLPnXkBKe+ipvoFhNQywOhdghvLi0F8ReyVXV4BKTBRbbe5f64zR/DHsdZw1hJfeWlHl/GNRJzDxrd5m192z78TMaVnKELZoINZS4BzQ7vtnZljSnha/pPCbkuxzXcupYwI5tIeCpGc0Yp9tWHZQy/rmYhRfNgg4bHJBYLzGkxsRJF4XKlE2jBOHNSv3kY7Tj6vthzPFl61BrYwqFlmEQhtSVXmLiksxLmtRgYXI1ULU61JJ4eVKmG3/5sCVgpbMT6OMJ2E08/29Xf3w6v4FnHdCjfWgXu/O8Z5mLdCkeRs2khHe1DqOtQwbHWTAnM5S2HNmhALYo5KjkPFrMMKjZl6HxhWIAb0BqE+/73GrBRQUsKYiBu4JX8ycI6wtw+i5ef3NZpsrKVSHYCP37jwGDgeE1SA0S/xtl5SU2fs1ApEp0qTLVRjgyycDSsLHMSwmFltZMStR3uLLg6BdLhDa5dC6ryU2pHBe1BVO9tUcwfitJt2CLJZUHoG6T7Op75u0IyK31TCPcwFqgPk/KCaD3dFOuZBCO7xvCT/j048b3I3c7F2+WuOW7qdgkucFYlcQ4qop3yzTX7WaKfOCccye3Ts1Etq0+a/BHCF1yPgF3tAUkR6OrtGmo6gl94qqcXKh3rDyrOkPa58URoWcov2Mo6M+0QjrqKB+b7++oMa9Sz+ZkM0mie6aAtnGUvhmxaI+TogPOSQedgWioGSHFLn3v4kLh4HRspNmOGv41k+55siLFp2z6xYeJjhljFcbmxJlr4ga06TbevSByz/glQq4BJx46/c+237PbBqEYKxX3HpmKZEnQnr65X20hqJYaNcLoFOLiJk2LuBbyg7Q0OEn+hm0P3honxFD6rdxYorKpeIoi4YSSvyQHQIbM5t4+YNxLj/OxhVOOE4585qGpjnq+wSx6Q9CtNxTjd5klB+g6Mv36r0+b9cZFi44WYkHdG2ZWb3TtOUOXyVAlKlpGvJIAJ3eBMyfYS5C0qRZGtC85j+4sOasDe9xznPYezhhO/2Q6eP2fSOvYHOjtuQ1a9Q1VKynVDaMc8E0tptdxUsTFpFIYjcZKcbnoaQTNdiqCwNlL4G7oziSqGnT1ALf34vhk4R5zU3qYV9ONp9K88RtouShE68JwaU8dFw5W617shWa9ykeaBIn2hcsvPgL00k45QdTCZuSVcTRNs+8fnyLvooQfR5iujAnR9bxfY2xOVOxFS8SK3Le0l48VyYu1M8HRe5JD8wKPTjYnifaK3Wfn/GChYQ8ZAi6WRzWgqLV5YrsVLnZaVSoXU1g9gOIDwFySiGi+Zdrnzr7J3r+SMuszlcQCRn8lNGcTuSy2jOI7o9mxjZo+vR3ej3tN+ifRSOyUTS0+VMOid93cCubeiy/6TImS0QxRSCq2vxKr45zV+FQnjWH6D2xg+E9EatLcLAdHTgtGGD80D6jM0+aOl4wJgO/f96R2aJKCQ3yvgftRhdFMOpd6oAAAAASUVORK5CYII="
						role="presentation" style="pointer-events: none;" width="16" height="16">
				</div>
			</div>
			<div class="js-toggle-thumb"></div>
			<input class="js-toggle-screenreader-only" type="checkbox" aria-label="Switch between Dark and Light mode">
		</div>
	</div>
</div>
<style>
	/*
* Dark Mode Toggle
* Copyright (c) 2015 instructure-react
* Forked from Dan Abramov's personal blog
* https://github.com/gaearon/overreacted.io/blob/master/src/components/Toggle.css
* MIT License
**/

	.js-toggle-wrapper {
		display: table;
		margin: 0 auto;
	}

	.js-toggle {
		touch-action: pan-x;
		display: inline-block;
		position: relative;
		cursor: pointer;
		background-color: transparent;
		border: 0;
		padding: 0;
		-webkit-touch-callout: none;
		user-select: none;
		-webkit-tap-highlight-color: rgba(0, 0, 0, 0);
		-webkit-tap-highlight-color: transparent;
	}

	.js-toggle-screenreader-only {
		border: 0;
		clip: rect(0 0 0 0);
		height: 1px;
		margin: -1px;
		overflow: hidden;
		padding: 0;
		position: absolute;
		width: 1px;
	}

	.js-toggle-track {
		width: 50px;
		height: 24px;
		padding: 0;
		border-radius: 30px;
		background-color: #808080;
		transition: all 0.2s ease;
	}

	.js-toggle-track-check {
		position: absolute;
		width: 17px;
		height: 17px;
		left: 5px;
		top: 0px;
		bottom: 0px;
		margin-top: auto;
		margin-bottom: auto;
		line-height: 0;
		opacity: 0;
		transition: opacity 0.25s ease;
	}

	.js-toggle--checked .js-toggle-track-check {
		opacity: 1;
		transition: opacity 0.25s ease;
	}

	.js-toggle-track-x {
		position: absolute;
		width: 17px;
		height: 17px;
		right: 5px;
		top: 0px;
		bottom: 0px;
		margin-top: auto;
		margin-bottom: auto;
		line-height: 0;
		opacity: 1;
		transition: opacity 0.25s ease;
	}

	.js-toggle--checked .js-toggle-track-x {
		opacity: 0;
	}

	.js-toggle-thumb {
		position: absolute;
		top: 1px;
		left: 1px;
		width: 22px;
		height: 22px;
		border-radius: 50%;
		background-color: #fafafa;
		box-sizing: border-box;
		transition: all 0.5s cubic-bezier(0.23, 1, 0.32, 1) 0ms;
		transform: translateX(0);
	}

	.js-toggle--checked .js-toggle-thumb {
		transform: translateX(26px);
		border-color: #19ab27;
	}

	.js-toggle--focus {
		filter: drop-shadow(0px 0px 3px var(--primary-accent));
		outline: 1px solid var(--ui-text);
		outline-offset: 6px;
	}

	.js-toggle:active .js-toggle-thumb {
		box-shadow: 0px 0px 5px 5px var(--primary-accent);
	}
</style>
<script>
	var body = document.body;
	var switchers = document.getElementsByClassName('js-toggle');

	for (switcher of switchers) {
		switcher.removeAttribute("style");
		var input = switcher.querySelector('.js-toggle-screenreader-only')

		input.addEventListener('focus', (event) => {
			switcher.classList.add('js-toggle--focus');
		});

		input.addEventListener('focusout', (event) => {
			switcher.classList.remove('js-toggle--focus');
		});

		//Click on dark mode icon. Add dark mode classes and wrappers. Store user preference through sessions
		switcher.addEventListener("click", function () {
			for (switcher of switchers) {
				this.classList.toggle('js-toggle--checked');
			}
			//this.classList.add('js-toggle--focus');
			//If dark mode is selected
			if (this.classList.contains('js-toggle--checked')) {
				body.classList.remove('light-mode');
				body.classList.add('dark-mode');
				//Save user preference in storage
				localStorage.setItem('colorMode', 'dark');
			} else {
				body.classList.remove('dark-mode');
				body.classList.add('light-mode');
				setTimeout(function () {
					localStorage.setItem('colorMode', 'light');
				}, 100);
			}
		})
	};

	if (window.matchMedia && window.matchMedia('(prefers-color-scheme: dark)').matches) {
		localStorage.setItem('colorMode', 'dark');
	}

	//Check Storage. Keep user preference on page reload
	if (localStorage.getItem('colorMode') == 'dark') {
		for (switcher of switchers) {
			switcher.classList.add('js-toggle--checked');
		}
		body.classList.add('dark-mode');
	};
	if (localStorage.getItem('colorMode') == 'light') {
		body.classList.add('light-mode');
	};

</script>