Add mail menu sidebar

frontend-js/dist/app.js

@@ -93,6 +93,30 @@
   window.addEventListener("DOMContentLoaded", () => bind(document.querySelector(".three-pane")));
 })();
 
+(function () {
+  function setOpen(open) {
+    document.body.classList.toggle("backstage-open", open);
+    document.querySelectorAll("[data-backstage-toggle]").forEach((button) => {
+      button.setAttribute("aria-expanded", open ? "true" : "false");
+    });
+  }
+
+  document.addEventListener("click", (event) => {
+    const toggle = event.target.closest("[data-backstage-toggle]");
+    if (toggle) {
+      setOpen(!document.body.classList.contains("backstage-open"));
+      return;
+    }
+    if (event.target.closest("[data-backstage-close]")) {
+      setOpen(false);
+    }
+  });
+
+  document.addEventListener("keydown", (event) => {
+    if (event.key === "Escape") setOpen(false);
+  });
+})();
+
 (function () {
   function rowPayload(row) {
     return {