Init

app/static/js/theme.js

@@ -0,0 +1,30 @@
+(() => {
+  const KEY = "wrapped.theme";
+
+  function preferred() {
+    return localStorage.getItem(KEY) || "dark";
+  }
+
+  function apply(theme) {
+    document.documentElement.setAttribute("data-theme", theme);
+    const sun = document.getElementById("theme-icon-sun");
+    const moon = document.getElementById("theme-icon-moon");
+    if (sun && moon) {
+      sun.classList.toggle("hidden", theme !== "light");
+      moon.classList.toggle("hidden", theme !== "dark");
+    }
+  }
+
+  function toggle() {
+    const next = preferred() === "dark" ? "light" : "dark";
+    localStorage.setItem(KEY, next);
+    apply(next);
+  }
+
+  apply(preferred());
+  document.addEventListener("DOMContentLoaded", () => {
+    apply(preferred());
+    const btn = document.getElementById("theme-toggle");
+    if (btn) btn.addEventListener("click", toggle);
+  });
+})();