diff --git a/js/ui/focusTrapStacking.js b/js/ui/focusTrapStacking.js
new file mode 100644
index 00000000..af29381b
--- /dev/null
+++ b/js/ui/focusTrapStacking.js
@@ -0,0 +1,13 @@
+// A focus trap (e.g. the profile modal's) must YIELD focus to any modal stacked on
+// top of it — otherwise it yanks focus back and the stacked modal's fields (like the
+// login modal's nsec passphrase/PIN input) can't be clicked or typed into.
+//
+// Returns true when the focus target lives inside a DIFFERENT open `.bv-modal` than the
+// trapping modal — i.e. the trap should leave focus alone.
+export function isInStackedModal(target, modalRoot) {
+  if (!target || typeof target.closest !== "function") {
+    return false;
+  }
+  const stacked = target.closest(".bv-modal:not(.hidden)");
+  return Boolean(stacked && stacked !== modalRoot);
+}
diff --git a/js/ui/profileModalController.js b/js/ui/profileModalController.js
index d44ed442..e5c293f2 100644
--- a/js/ui/profileModalController.js
+++ b/js/ui/profileModalController.js
@@ -51,6 +51,7 @@ import { ProfileAdminController } from "./profileModal/ProfileAdminController.js
 import { ProfileModerationController } from "./profileModal/ProfileModerationController.js";
 import { ProfileBlockListController } from "./profileModal/ProfileBlockListController.js";
 import { ProfileEditController } from "./profileModal/ProfileEditController.js";
+import { isInStackedModal } from "./focusTrapStacking.js";
 
 const noop = () => {};
 
@@ -4670,6 +4671,12 @@ export class ProfileModalController {
           return;
         }
 
+        // Don't fight a modal stacked on top of the profile modal (e.g. the login
+        // modal's nsec passphrase/PIN field) — let it own focus so it stays typable.
+        if (isInStackedModal(event.target, modalRoot)) {
+          return;
+        }
+
         const fallback =
           this.focusableElements[0] ||
           this.profileModalPanel ||
diff --git a/tests/focus-trap-stacking.test.mjs b/tests/focus-trap-stacking.test.mjs
new file mode 100644
index 00000000..414a4c3a
--- /dev/null
+++ b/tests/focus-trap-stacking.test.mjs
@@ -0,0 +1,57 @@
+// Bug: opening the login modal's nsec passphrase/PIN field on top of the profile modal
+// left it unclickable/untypable — the profile modal's focusin trap yanked focus back
+// because it didn't recognize the stacked login modal. isInStackedModal() is the guard
+// that makes the trap yield to a modal stacked on top.
+
+import test from "node:test";
+import { strict as assert } from "node:assert";
+import { JSDOM } from "jsdom";
+import { isInStackedModal } from "../js/ui/focusTrapStacking.js";
+
+const dom = new JSDOM(`<!doctype html><html><body>
+  <div id="profileModal" class="bv-modal">
+    <input id="profileInput" />
+  </div>
+  <div id="loginModal" class="bv-modal">
+    <input id="pinInput" />
+  </div>
+  <div id="closedModal" class="bv-modal hidden">
+    <input id="closedInput" />
+  </div>
+  <input id="bareInput" />
+</body></html>`);
+const { document } = dom.window;
+const profileModal = document.getElementById("profileModal");
+
+test("yields focus to an input inside a different OPEN modal (the login PIN field)", () => {
+  assert.equal(
+    isInStackedModal(document.getElementById("pinInput"), profileModal),
+    true,
+  );
+});
+
+test("does NOT yield for focus moving inside the trapping modal itself", () => {
+  assert.equal(
+    isInStackedModal(document.getElementById("profileInput"), profileModal),
+    false,
+  );
+});
+
+test("does NOT yield to a HIDDEN modal's field", () => {
+  assert.equal(
+    isInStackedModal(document.getElementById("closedInput"), profileModal),
+    false,
+  );
+});
+
+test("does NOT yield for a target that isn't in any modal (trap should reclaim focus)", () => {
+  assert.equal(
+    isInStackedModal(document.getElementById("bareInput"), profileModal),
+    false,
+  );
+});
+
+test("safe for a null / non-element target", () => {
+  assert.equal(isInStackedModal(null, profileModal), false);
+  assert.equal(isInStackedModal({}, profileModal), false);
+});