diff --git a/site/src/components/LangPicker.astro b/site/src/components/LangPicker.astro
index 1c6ec6b..16f96ab 100644
--- a/site/src/components/LangPicker.astro
+++ b/site/src/components/LangPicker.astro
@@ -1,5 +1,5 @@
 ---
-import { locales, defaultLocale, type Locale } from "../i18n/ui";
+import { locales, localizePath, type Locale } from "../i18n/ui";
 
 interface Props {
   locale: Locale;
@@ -13,7 +13,7 @@ const labels: Record<Locale, string> = {
   fr: "FR",
   es: "ES",
 };
-const href = (l: Locale) => (l === defaultLocale ? path : `/${l}${path}`);
+const href = (l: Locale) => localizePath(l, path);
 ---
 <div class="flex items-center gap-2 text-sm">
   {locales.map((l) => (
diff --git a/site/src/components/Nav.astro b/site/src/components/Nav.astro
index a39774d..6116eb1 100644
--- a/site/src/components/Nav.astro
+++ b/site/src/components/Nav.astro
@@ -1,5 +1,5 @@
 ---
-import { defaultLocale, useTranslations, type Locale } from "../i18n/ui";
+import { localizePath, useTranslations, type Locale } from "../i18n/ui";
 import ThemeToggle from "./ThemeToggle.astro";
 import LangPicker from "./LangPicker.astro";
 
@@ -9,7 +9,7 @@ interface Props {
 }
 const { locale, path } = Astro.props;
 const t = useTranslations(locale);
-const p = (sub: string) => (locale === defaultLocale ? sub : `/${locale}${sub}`);
+const p = (sub: string) => localizePath(locale, sub);
 ---
 <header class="sticky top-0 z-50 border-b border-line bg-mantle/90 backdrop-blur">
   <nav class="mx-auto flex max-w-5xl items-center justify-between px-4 py-3">
@@ -17,12 +17,26 @@ const p = (sub: string) => (locale === defaultLocale ? sub : `/${locale}${sub}`)
       <img src="/assets/images/termscp.webp" alt="termscp" class="h-7 w-7" />
       <span class="font-bold">termscp</span>
     </a>
-    <div class="flex items-center gap-5 text-sm">
+
+    <!-- Desktop -->
+    <div class="hidden items-center gap-5 text-sm sm:flex">
       <a href={p("/install")} class="text-overlay hover:text-text">{t("nav.install")}</a>
       <a href={p("/user-manual")} class="text-overlay hover:text-text">{t("nav.manual")}</a>
       <a href="https://github.com/veeso/termscp" class="text-overlay hover:text-text">{t("nav.github")}</a>
       <LangPicker locale={locale} path={path} />
       <ThemeToggle />
     </div>
+
+    <!-- Mobile -->
+    <details class="relative sm:hidden">
+      <summary class="cursor-pointer list-none rounded p-2 text-text hover:bg-mantle" aria-label="Menu">☰</summary>
+      <div class="absolute right-0 mt-2 flex w-48 flex-col gap-3 rounded-lg border border-line bg-mantle p-4 text-sm shadow-xl">
+        <a href={p("/install")} class="text-overlay hover:text-text">{t("nav.install")}</a>
+        <a href={p("/user-manual")} class="text-overlay hover:text-text">{t("nav.manual")}</a>
+        <a href="https://github.com/veeso/termscp" class="text-overlay hover:text-text">{t("nav.github")}</a>
+        <LangPicker locale={locale} path={path} />
+        <ThemeToggle />
+      </div>
+    </details>
   </nav>
 </header>
diff --git a/site/src/components/ThemeToggle.astro b/site/src/components/ThemeToggle.astro
index a8a1c03..f0bf667 100644
--- a/site/src/components/ThemeToggle.astro
+++ b/site/src/components/ThemeToggle.astro
@@ -1,32 +1,31 @@
 ---
-// Tiny client island: flips data-theme + persists. Contract: writes "frappe"|"latte".
+// Theme toggle. Contract: localStorage 'theme' = "frappe" | "latte". Safe to render multiple times.
 ---
 <button
-  id="theme-toggle"
   type="button"
+  data-theme-toggle
   aria-label="Toggle theme"
+  aria-pressed="false"
   class="rounded p-2 text-text hover:bg-mantle"
 >
   <span data-icon="frappe">☾</span>
-  <span data-icon="latte" hidden>☀</span>
+  <span data-icon="latte">☀</span>
 </button>
 <script is:inline>
   (() => {
-    const btn = document.getElementById("theme-toggle");
-    const sync = () => {
-      const t = document.documentElement.getAttribute("data-theme");
-      btn.querySelector('[data-icon="frappe"]').hidden = t !== "frappe";
-      btn.querySelector('[data-icon="latte"]').hidden = t !== "latte";
-    };
-    btn.addEventListener("click", () => {
-      const next =
-        document.documentElement.getAttribute("data-theme") === "frappe"
-          ? "latte"
-          : "frappe";
-      document.documentElement.setAttribute("data-theme", next);
-      localStorage.setItem("theme", next);
-      sync();
-    });
-    sync();
+    if (window.__themeToggleInit) return;
+    window.__themeToggleInit = true;
+    const root = document.documentElement;
+    const btns = document.querySelectorAll("[data-theme-toggle]");
+    const setPressed = () => btns.forEach((b) =>
+      b.setAttribute("aria-pressed", String(root.getAttribute("data-theme") === "latte")));
+    btns.forEach((b) =>
+      b.addEventListener("click", () => {
+        const next = root.getAttribute("data-theme") === "frappe" ? "latte" : "frappe";
+        root.setAttribute("data-theme", next);
+        localStorage.setItem("theme", next);
+        setPressed();
+      }));
+    setPressed();
   })();
 </script>
diff --git a/site/src/i18n/ui.ts b/site/src/i18n/ui.ts
index 4f00424..a8084f8 100644
--- a/site/src/i18n/ui.ts
+++ b/site/src/i18n/ui.ts
@@ -25,6 +25,11 @@ export function isLocale(value: string): value is Locale {
   return (locales as readonly string[]).includes(value);
 }
 
+/** Prefix a path with the locale, except for the default locale. */
+export function localizePath(locale: Locale, path: string): string {
+  return locale === defaultLocale ? path : `/${locale}${path}`;
+}
+
 /** Resolve a translator for `locale`, falling back to en, then to the key. */
 export function useTranslations(locale: Locale) {
   const dict = dictionaries[locale] ?? dictionaries[defaultLocale];
diff --git a/site/src/styles/theme.css b/site/src/styles/theme.css
index 89e6fdf..99bf32e 100644
--- a/site/src/styles/theme.css
+++ b/site/src/styles/theme.css
@@ -79,6 +79,11 @@ html {
   color: var(--color-text);
 }
 
+/* Theme toggle icons: shown based on active theme, set before paint by the head bootstrap */
+[data-icon] { display: none; }
+[data-theme="frappe"] [data-icon="frappe"] { display: inline; }
+[data-theme="latte"] [data-icon="latte"] { display: inline; }
+
 .blink {
   display: inline-block;
   width: 0.5rem;