diff --git a/src/_data/sites/de.yml b/src/_data/sites/de.yml
index 7ad2f037f6..b061a93666 100644
--- a/src/_data/sites/de.yml
+++ b/src/_data/sites/de.yml
@@ -90,6 +90,7 @@ footer:
     mastodon: Mastodon
   theme_switcher:
     title: Themenauswahl
+    system: System
     light: Hell
     dark: Dunkel
   language_switcher:
diff --git a/src/_data/sites/en.yml b/src/_data/sites/en.yml
index bb331bfeca..647c6f7cda 100644
--- a/src/_data/sites/en.yml
+++ b/src/_data/sites/en.yml
@@ -95,6 +95,7 @@ footer:
     mastodon: Mastodon
   theme_switcher:
     title: Theme Switcher
+    system: System
     light: Light
     dark: Dark
   language_switcher:
diff --git a/src/_data/sites/es.yml b/src/_data/sites/es.yml
index 5fb700b291..0c859deee4 100644
--- a/src/_data/sites/es.yml
+++ b/src/_data/sites/es.yml
@@ -88,6 +88,7 @@ footer:
     mastodon: Mastodon
   theme_switcher:
     title: Cambiar temas
+    system: Sistema
     light: Claro
     dark: Oscuro
   language_switcher:
diff --git a/src/_data/sites/fr.yml b/src/_data/sites/fr.yml
index 7434fc2fb8..2ec59f7d72 100644
--- a/src/_data/sites/fr.yml
+++ b/src/_data/sites/fr.yml
@@ -89,6 +89,7 @@ footer:
     mastodon: Mastodon
   theme_switcher:
     title: Thèmes
+    system: Système
     light: Light
     dark: Dark
   language_switcher:
diff --git a/src/_data/sites/hi.yml b/src/_data/sites/hi.yml
index 7ea2689f78..81540c2dec 100644
--- a/src/_data/sites/hi.yml
+++ b/src/_data/sites/hi.yml
@@ -87,6 +87,7 @@ footer:
     mastodon: Mastodon
   theme_switcher:
     title: Theme Switcher
+    system: System
     light: Light
     dark: Dark
   language_switcher:
diff --git a/src/_data/sites/ja.yml b/src/_data/sites/ja.yml
index 9f7df42373..36f7bbc9f3 100644
--- a/src/_data/sites/ja.yml
+++ b/src/_data/sites/ja.yml
@@ -88,6 +88,7 @@ footer:
     mastodon: Mastodon
   theme_switcher:
     title: 配色モード切り替え
+    system: システム
     light: 通常
     dark: ダーク
   language_switcher:
diff --git a/src/_data/sites/pt-br.yml b/src/_data/sites/pt-br.yml
index 7ef5f2200b..591f985d4b 100644
--- a/src/_data/sites/pt-br.yml
+++ b/src/_data/sites/pt-br.yml
@@ -88,6 +88,7 @@ footer:
     mastodon: Mastodon
   theme_switcher:
     title: Trocar tema
+    system: Sistema
     light: Claro
     dark: Escuro
   language_switcher:
diff --git a/src/_data/sites/zh-hans.yml b/src/_data/sites/zh-hans.yml
index 63b555fc22..d0642fe604 100644
--- a/src/_data/sites/zh-hans.yml
+++ b/src/_data/sites/zh-hans.yml
@@ -87,6 +87,7 @@ footer:
     mastodon: Mastodon
   theme_switcher:
     title: 主题切换
+    system: 系统
     light: 浅色
     dark: 深色
   language_switcher:
diff --git a/src/_includes/components/theme-switcher.html b/src/_includes/components/theme-switcher.html
index 39e6a11158..cb44e85c49 100644
--- a/src/_includes/components/theme-switcher.html
+++ b/src/_includes/components/theme-switcher.html
@@ -5,6 +5,10 @@ <h2 class="theme-switcher-label visually-hidden" id="theme-switcher-label">{{ si
             <svg class="theme-switcher__icon" focusable="false" width="22" height="22" viewBox="0 0 100 100" aria-hidden="true"><g transform="translate(0,-952.36218)"><path d="m 50,955.36218 c 1.6568,0 3,1.3431 3,3 l 0,16 c 0,1.6569 -1.3432,3 -3,3 -1.6569,0 -3,-1.3431 -3,-3 l 0,-16 c 0,-1.6569 1.3431,-3 3,-3 z m 31.125,12.875 c 0.76777,0 1.50798,0.3205 2.09375,0.9062 1.17159,1.1717 1.17157,3.0472 0,4.2188 l -11.3125,11.3125 c -1.17157,1.1716 -3.04714,1.1716 -4.21875,0 -1.17153,-1.1715 -1.17158,-3.0472 0,-4.2187 L 79,969.14338 c 0.58579,-0.5857 1.35723,-0.9062 2.125,-0.9062 z m -62.25,0 c 0.76777,0 1.53921,0.3205 2.125,0.9062 l 11.3125,11.3126 c 1.17158,1.1715 1.17153,3.0472 0,4.2187 -1.17161,1.1716 -3.04718,1.1716 -4.21875,0 l -11.3125,-11.3125 c -1.17157,-1.1716 -1.17159,-3.0471 0,-4.2188 0.58577,-0.5857 1.32598,-0.9062 2.09375,-0.9062 z M 50,983.36218 c 10.45786,0 19,8.5422 19,19.00002 0,10.4579 -8.54214,19 -19,19 -10.45784,0 -19,-8.5421 -19,-19 0,-10.45792 8.54216,-19.00002 19,-19.00002 z m 0,6 c -7.21516,0 -13,5.7848 -13,13.00002 0,7.2152 5.78484,13 13,13 7.21518,0 13,-5.7848 13,-13 0,-7.21522 -5.78482,-13.00002 -13,-13.00002 z m 44,10 c 1.65686,0 2.99999,1.34322 3,3.00002 -1e-5,1.6569 -1.34315,3 -3,3 l -16,0 c -1.65685,0 -3,-1.3431 -3,-3 0,-1.6568 1.34316,-3.00002 3,-3.00002 l 16,0 z m -72,0 c 1.65684,0 3,1.34322 3,3.00002 0,1.6569 -1.34315,3 -3,3 l -16,0 c -1.65685,0 -2.99999,-1.3431 -3,-3 1e-5,-1.6568 1.34314,-3.00002 3,-3.00002 l 16,0 z m 47.8125,19.81252 c 0.76777,0 1.50797,0.2892 2.09375,0.875 l 11.3125,11.3125 c 1.17158,1.1716 1.17152,3.0472 0,4.2188 -1.1716,1.1715 -3.04718,1.1715 -4.21875,0 l -11.3125,-11.3126 c -1.17157,-1.1715 -1.1716,-3.0471 0,-4.2187 0.58577,-0.5858 1.35723,-0.875 2.125,-0.875 z m -39.625,0 c 0.76777,0 1.53923,0.2892 2.125,0.875 1.1716,1.1716 1.17157,3.0472 0,4.2187 L 21,1035.581 c -1.17157,1.1715 -3.04715,1.1715 -4.21875,0 -1.17152,-1.1716 -1.17158,-3.0472 0,-4.2188 l 11.3125,-11.3125 c 0.58578,-0.5858 1.32598,-0.875 2.09375,-0.875 z M 50,1027.3622 c 1.6568,0 3,1.3431 3,3 l 0,16 c 0,1.6569 -1.3432,3 -3,3 -1.6569,0 -3,-1.3431 -3,-3 l 0,-16 c 0,-1.6569 1.3431,-3 3,-3 z" fill="currentColor" fill-opacity="1" stroke="none"></path></g></svg>
             <span>{{ site.footer.theme_switcher.light }}</span>
         </button>
+        <button class="theme-switcher__button js-toggle-button" id="system-theme-toggle" data-theme="system">
+            <svg class="theme-switcher__icon" focusable="false" width="22" height="22" viewBox="0 0 24 24" aria-hidden="true" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="feather feather-monitor"><rect x="2" y="3" width="20" height="14" rx="2" ry="2"></rect><line x1="8" y1="21" x2="16" y2="21"></line><line x1="12" y1="17" x2="12" y2="21"></line></svg>
+            <span>{{ site.footer.theme_switcher.system }}</span>
+        </button>
         <button class="theme-switcher__button js-toggle-button" id="dark-theme-toggle" data-theme="dark">
             <svg class="theme-switcher__icon" focusable="false" width="22" height="22" viewBox="0 0 100 100" aria-hidden="true"><g transform="translate(0,-952.36218)"><path d="m 35.377874,961.36325 a 3.0003,3.0003 0 0 0 -0.9063,0.1875 c -16.1759,5.9947 -25.4686997,21.7109 -25.4686997,39.59375 0,23.2769 18.9104997,42.2187 42.1873997,42.2187 17.8829,0 33.6304,-9.324 39.625,-25.5 a 3.0003,3.0003 0 0 0 -3.9374,-3.8125 c -4.0936,1.6462 -8.5949,2.5 -13.3438,2.5 -19.5969,0 -37.7188,-18.15315 -37.7188,-37.74995 0,-4.7489 0.8226,-9.2504 2.4688,-13.3437 a 3.0003,3.0003 0 0 0 -2.9062,-4.0938 z m -4.6563,8.7188 c -0.5822,2.8241 -0.9063,5.7363 -0.9063,8.7187 0,23.21085 20.5079,43.74995 43.7188,43.74995 2.9824,0 5.8946,-0.3553 8.7188,-0.9375 -6.2657,10.0487 -17.6431,15.75 -31.0626,15.75 -20.0342,0 -36.1874,-16.1844 -36.1874,-36.2187 0,-13.42105 5.6679,-24.79725 15.7187,-31.06245 z" fill="currentColor" fill-opacity="1" stroke="none"></path></g></svg>
             <span>{{ site.footer.theme_switcher.dark }}</span>
diff --git a/src/_includes/layouts/base.html b/src/_includes/layouts/base.html
index ff59a1cbd5..f17a61c798 100644
--- a/src/_includes/layouts/base.html
+++ b/src/_includes/layouts/base.html
@@ -77,7 +77,7 @@
     <script>
             (function () {
                 var theme = window.localStorage.getItem("theme");
-                if (theme) document.documentElement.setAttribute('data-theme', theme)
+                if (theme && theme !== "system") document.documentElement.setAttribute('data-theme', theme)
                 else if (window.matchMedia('(prefers-color-scheme: dark)').matches)
                     document.documentElement.setAttribute('data-theme', 'dark');
                 else document.documentElement.setAttribute('data-theme', 'light');
diff --git a/src/assets/js/themes.js b/src/assets/js/themes.js
index 46b7c746c5..d63c9d4b4b 100644
--- a/src/assets/js/themes.js
+++ b/src/assets/js/themes.js
@@ -1,57 +1,78 @@
-/* theme toggle buttons */
 (function () {
 	var enableToggle = function (btn) {
 		btn.setAttribute("aria-pressed", "true");
 	};
-	var disableToggle = function (btn) {
-		btn.setAttribute("aria-pressed", "false");
+
+	var disableToggle = function (btns) {
+		btns.forEach(btn => btn.setAttribute("aria-pressed", "false"));
 	};
+
 	var setTheme = function (theme) {
-		document.documentElement.setAttribute("data-theme", theme);
+		if (theme === "system") {
+			var systemTheme = window.matchMedia("(prefers-color-scheme: dark)")
+				.matches
+				? "dark"
+				: "light";
+			document.documentElement.setAttribute("data-theme", systemTheme);
+		} else {
+			document.documentElement.setAttribute("data-theme", theme);
+		}
 		window.localStorage.setItem("theme", theme);
 	};
 
-	var theme = document.documentElement.getAttribute("data-theme");
-
-	document.addEventListener(
-		"DOMContentLoaded",
-		function () {
-			var switcher = document.getElementById("js-theme-switcher");
-			switcher.removeAttribute("hidden");
-			var light_theme_toggle =
-					document.getElementById("light-theme-toggle"),
-				dark_theme_toggle =
-					document.getElementById("dark-theme-toggle");
-			if (theme) {
-				if (theme === "light") {
-					enableToggle(light_theme_toggle);
-					disableToggle(dark_theme_toggle);
-				} else if (theme === "dark") {
-					enableToggle(dark_theme_toggle);
-					disableToggle(light_theme_toggle);
+	var initializeThemeSwitcher = function () {
+		var theme = window.localStorage.getItem("theme") || "system";
+		var switcher = document.getElementById("js-theme-switcher");
+		switcher.removeAttribute("hidden");
+
+		var lightThemeToggle = document.getElementById("light-theme-toggle");
+		var darkThemeToggle = document.getElementById("dark-theme-toggle");
+		var systemThemeToggle = document.getElementById("system-theme-toggle");
+
+		var toggleButtons = [
+			lightThemeToggle,
+			darkThemeToggle,
+			systemThemeToggle,
+		];
+
+		toggleButtons.forEach(function (btn) {
+			btn.addEventListener("click", function () {
+				enableToggle(btn);
+				var theme = this.getAttribute("data-theme");
+				setTheme(theme);
+				if (btn === systemThemeToggle) {
+					disableToggle([lightThemeToggle, darkThemeToggle]);
+				} else if (btn === lightThemeToggle) {
+					disableToggle([systemThemeToggle, darkThemeToggle]);
+				} else if (btn === darkThemeToggle) {
+					disableToggle([systemThemeToggle, lightThemeToggle]);
 				}
-			}
-			light_theme_toggle.addEventListener(
-				"click",
-				function () {
-					enableToggle(light_theme_toggle);
-					theme = this.getAttribute("data-theme");
-					setTheme(theme);
-					disableToggle(dark_theme_toggle);
-				},
-				false,
-			);
-			dark_theme_toggle.addEventListener(
-				"click",
-				function () {
-					enableToggle(dark_theme_toggle);
-					theme = this.getAttribute("data-theme");
-					setTheme(theme);
-					disableToggle(light_theme_toggle);
-				},
-				false,
-			);
-		},
-		false,
-	);
+			});
+		});
+
+		if (theme === "system") {
+			enableToggle(systemThemeToggle);
+			disableToggle([lightThemeToggle, darkThemeToggle]);
+		} else if (theme === "light") {
+			enableToggle(lightThemeToggle);
+			disableToggle([systemThemeToggle, darkThemeToggle]);
+		} else if (theme === "dark") {
+			enableToggle(darkThemeToggle);
+			disableToggle([systemThemeToggle, lightThemeToggle]);
+		}
+
+		// Update theme on system preference change
+		window
+			.matchMedia("(prefers-color-scheme: dark)")
+			.addEventListener("change", function () {
+				var currentTheme = window.localStorage.getItem("theme");
+				if (currentTheme === "system" || !currentTheme) {
+					enableToggle(systemThemeToggle);
+					disableToggle([lightThemeToggle, darkThemeToggle]);
+					setTheme("system");
+				}
+			});
+	};
+
+	document.addEventListener("DOMContentLoaded", initializeThemeSwitcher);
 })();
diff --git a/src/assets/scss/components/theme-switcher.scss b/src/assets/scss/components/theme-switcher.scss
index 77d279257f..87338c4d26 100644
--- a/src/assets/scss/components/theme-switcher.scss
+++ b/src/assets/scss/components/theme-switcher.scss
@@ -29,6 +29,13 @@
 	gap: 0.25rem;
 	color: inherit;
 
+	@media screen and (min-width: 1121px) and (max-width: 1200px) {
+		padding: 0.625rem 0.675rem;
+	}
+	@media screen and (min-width: 1023px) and (max-width: 1120px) {
+		padding: 0.625rem 0.375rem;
+	}
+
 	&:first-of-type {
 		border-right: 0.5px solid var(--border-color);
 		border-inline-end: 0.5px solid var(--border-color);
diff --git a/src/assets/scss/footer.scss b/src/assets/scss/footer.scss
index f8257310fd..bf408fed23 100644
--- a/src/assets/scss/footer.scss
+++ b/src/assets/scss/footer.scss
@@ -57,9 +57,10 @@
 	align-items: center;
 	gap: 2rem;
 
-	@media all and (min-width: 768px) {
+	@media all and (min-width: 800px) {
 		flex-direction: row;
 		justify-content: space-between;
+		gap: 1.2rem;
 	}
 }
 
diff --git a/src/playground/components/ThemeSwitcher.js b/src/playground/components/ThemeSwitcher.js
index 246348dce4..8212dca7e1 100644
--- a/src/playground/components/ThemeSwitcher.js
+++ b/src/playground/components/ThemeSwitcher.js
@@ -1,16 +1,41 @@
-import React, { useState } from "react";
+import React, { useEffect, useState } from "react";
 
 export default function ThemeSwitcher() {
-	const [theme, setTheme] = useState(
-		document.documentElement.getAttribute("data-theme"),
-	);
+	const [theme, setTheme] = useState(window.localStorage.getItem("theme"));
 
 	const toggleTheme = newTheme => {
-		setTheme(newTheme);
-		document.documentElement.setAttribute("data-theme", newTheme);
+		if (newTheme === "system") {
+			const currentSystemTheme = window.matchMedia(
+				"(prefers-color-scheme: dark)",
+			).matches
+				? "dark"
+				: "light";
+			document.documentElement.setAttribute(
+				"data-theme",
+				currentSystemTheme,
+			);
+		} else {
+			document.documentElement.setAttribute("data-theme", newTheme);
+		}
 		window.localStorage.setItem("theme", newTheme);
+		setTheme(newTheme);
 	};
 
+	useEffect(() => {
+		const media = window.matchMedia("(prefers-color-scheme: dark)");
+
+		function onChangeMedia() {
+			const currentTheme = window.localStorage.getItem("theme");
+
+			if (currentTheme === "system" || !currentTheme) {
+				toggleTheme("system");
+			}
+		}
+
+		media.addEventListener("change", onChangeMedia);
+		return () => media.removeEventListener("change", onChangeMedia);
+	}, []);
+
 	return (
 		<div
 			role="region"
@@ -52,6 +77,41 @@ export default function ThemeSwitcher() {
 					</svg>
 					<span>Light</span>
 				</button>
+				<button
+					className="theme-switcher__button js-toggle-button"
+					id="system-theme-toggle"
+					data-theme="system"
+					onClick={() => {
+						toggleTheme("system");
+					}}
+					aria-pressed={theme === "system"}
+				>
+					<svg
+						className="theme-switcher__icon"
+						focusable="false"
+						width="22"
+						height="22"
+						viewBox="0 0 24 24"
+						aria-hidden="true"
+						fill="none"
+						stroke="currentColor"
+						strokeWidth="2"
+						strokeLinecap="round"
+						strokeLinejoin="round"
+					>
+						<rect
+							x="2"
+							y="3"
+							width="20"
+							height="14"
+							rx="2"
+							ry="2"
+						></rect>
+						<line x1="8" y1="21" x2="16" y2="21"></line>
+						<line x1="12" y1="17" x2="12" y2="21"></line>
+					</svg>
+					<span>System</span>
+				</button>
 				<button
 					className="theme-switcher__button js-toggle-button"
 					onClick={() => {