Merge e56020d086 into 393441faa1

public/theme.js

@@ -0,0 +1,108 @@
+
+(() => {
+  const KEY = "convertx-theme";
+  const root = document.documentElement;
+  const mql = window.matchMedia?.("(prefers-color-scheme: dark)");
+
+  const getStoredTheme = () => {
+    try {
+      const v = localStorage.getItem(KEY);
+      return v === "dark" || v === "light" ? v : null;
+    } catch {
+      return null;
+    }
+  };
+
+  const getSystemTheme = () => (mql && mql.matches ? "dark" : "light");
+
+  const applyColorSchemeOnly = (theme) => {
+    // Hint to the browser for built-in UI (form controls, scrollbars, etc.)
+    root.style.colorScheme = theme === "dark" ? "dark" : "light";
+  };
+
+  const setTheme = (theme, { persist } = { persist: true }) => {
+    if (theme !== "dark" && theme !== "light") return;
+
+    root.setAttribute("data-theme", theme);
+    applyColorSchemeOnly(theme);
+
+    if (persist) {
+      try {
+        localStorage.setItem(KEY, theme);
+      } catch {
+        // ignore
+      }
+    }
+  };
+
+  const clearThemeOverride = () => {
+    root.removeAttribute("data-theme");
+    try {
+      localStorage.removeItem(KEY);
+    } catch {
+      // ignore
+    }
+    // Important: even in auto-mode we still set color-scheme to system theme.
+    applyColorSchemeOnly(getSystemTheme());
+  };
+
+  const getEffectiveTheme = () => getStoredTheme() ?? getSystemTheme();
+
+  const syncUI = () => {
+    const checkbox = document.getElementById("cx-theme-switch");
+    const label = document.getElementById("cx-theme-label");
+    if (!checkbox && !label) return;
+
+    const theme = getEffectiveTheme();
+
+    if (checkbox) {
+      checkbox.checked = theme === "dark";
+      checkbox.setAttribute("aria-checked", checkbox.checked ? "true" : "false");
+    }
+
+    if (label) {
+      label.textContent = theme === "dark" ? "Dark" : "Light";
+    }
+  };
+
+  // --- Initial state ---
+  const stored = getStoredTheme();
+
+  if (stored) {
+    // Explicit override: lock both tokens + native controls.
+    setTheme(stored, { persist: false });
+  } else {
+    // Auto mode: follow OS, but ensure native controls match.
+    applyColorSchemeOnly(getSystemTheme());
+  }
+
+  document.addEventListener("DOMContentLoaded", () => {
+    syncUI();
+
+    const checkbox = document.getElementById("cx-theme-switch");
+    if (!checkbox) return;
+
+    checkbox.addEventListener("change", () => {
+      setTheme(checkbox.checked ? "dark" : "light", { persist: true });
+      syncUI();
+    });
+  });
+
+
+  if (mql) {
+    const onChange = () => {
+      if (getStoredTheme() == null) {
+        // Keep auto: no data-theme, but update color-scheme + UI.
+        root.removeAttribute("data-theme");
+        applyColorSchemeOnly(getSystemTheme());
+        syncUI();
+      }
+    };
+
+    if (typeof mql.addEventListener === "function") {
+      mql.addEventListener("change", onChange);
+    } else if (typeof mql.addListener === "function") {
+      mql.addListener(onChange);
+    }
+  }
+})();