diff --git a/src/app/signup/page.tsx b/src/app/signup/page.tsx
index 87a86c9..165e2cb 100644
--- a/src/app/signup/page.tsx
+++ b/src/app/signup/page.tsx
@@ -9,7 +9,7 @@ export const metadata = { title: "Sign up — Octo" };
 
 export default function SignupPage() {
   return (
-    <AuthShell>
+    <AuthShell consent>
       <AuthForm mode="signup" />
     </AuthShell>
   );
diff --git a/src/components/auth/AuthShell.tsx b/src/components/auth/AuthShell.tsx
index 56d3152..afde3b1 100644
--- a/src/components/auth/AuthShell.tsx
+++ b/src/components/auth/AuthShell.tsx
@@ -5,7 +5,14 @@ import { AuthWalletScene } from "@/components/auth/AuthWalletScene";
 
 /** Split-screen auth layout: glass form card on the left, brand copy on the
  *  right, both floating over a full-screen underwater "secure deposits" scene. */
-export function AuthShell({ children }: { children: React.ReactNode }) {
+export function AuthShell({
+  children,
+  consent = false,
+}: {
+  children: React.ReactNode;
+  /** Show the signup consent line. Only the signup page sets it. */
+  consent?: boolean;
+}) {
   return (
     <div className="relative min-h-screen">
       {/* Fixed backdrop: burgundy glow + faint isometric grid. The underwater
@@ -46,21 +53,19 @@ export function AuthShell({ children }: { children: React.ReactNode }) {
               </div>
               {children}
 
-              <p className="mx-auto mt-8 max-w-sm text-center text-xs text-muted">
-                By signing up, you agree to our{" "}
-                <Link href="/terms" className="underline">
-                  Terms
-                </Link>{" "}
-                and{" "}
-                <Link href="/terms" className="underline">
-                  Conditions of use
-                </Link>{" "}
-                and{" "}
-                <Link href="/privacy" className="underline">
-                  Privacy policy
-                </Link>
-                .
-              </p>
+              {consent && (
+                <p className="mx-auto mt-8 max-w-sm text-center text-xs text-muted">
+                  By signing up, you agree to our{" "}
+                  <Link href="/terms" className="underline">
+                    Terms of Service
+                  </Link>{" "}
+                  and{" "}
+                  <Link href="/privacy" className="underline">
+                    Privacy policy
+                  </Link>
+                  .
+                </p>
+              )}
             </div>
           </div>
         </div>
diff --git a/src/components/auth/OtpInput.tsx b/src/components/auth/OtpInput.tsx
index 99f9cf9..42026d7 100644
--- a/src/components/auth/OtpInput.tsx
+++ b/src/components/auth/OtpInput.tsx
@@ -7,10 +7,14 @@ export function OtpInput({
   value,
   onChange,
   disabled,
+  "aria-describedby": describedBy,
+  "aria-invalid": invalid,
 }: {
   value: string;
   onChange: (code: string) => void;
   disabled?: boolean;
+  "aria-describedby"?: string;
+  "aria-invalid"?: "true" | "false";
 }) {
   const inputs = useRef<Array<HTMLInputElement | null>>([]);
   const digits = Array.from({ length: 6 }, (_, i) => value[i] ?? "");
@@ -50,6 +54,8 @@ export function OtpInput({
           inputMode="numeric"
           autoComplete={i === 0 ? "one-time-code" : "off"}
           aria-label={`Digit ${i + 1} of 6`}
+          aria-describedby={describedBy}
+          aria-invalid={invalid}
           maxLength={1}
           className="h-12 w-10 rounded-lg border border-border bg-surface-sunken text-center text-lg font-semibold text-foreground focus:border-burgundy-bright focus:outline-none disabled:opacity-60"
         />
diff --git a/src/components/checkout/PayerPrivacyNotice.tsx b/src/components/checkout/PayerPrivacyNotice.tsx
index f1ed486..b0b43de 100644
--- a/src/components/checkout/PayerPrivacyNotice.tsx
+++ b/src/components/checkout/PayerPrivacyNotice.tsx
@@ -2,7 +2,16 @@
 export function PayerPrivacyNotice({ merchantName }: { merchantName: string }) {
   return (
     <p className="mt-1 text-[11px] text-gray-500">
-      Shared with {merchantName} and Octo to process this payment. See our Privacy Policy.
+      Shared with {merchantName} and Octo to process this payment. See our{" "}
+      <a
+        href="/privacy"
+        target="_blank"
+        rel="noopener noreferrer"
+        className="underline hover:no-underline"
+      >
+        Privacy Policy
+      </a>
+      .
     </p>
   );
 }
diff --git a/src/components/dashboard/Modal.tsx b/src/components/dashboard/Modal.tsx
index 9f40e30..f3f42da 100644
--- a/src/components/dashboard/Modal.tsx
+++ b/src/components/dashboard/Modal.tsx
@@ -1,10 +1,33 @@
 "use client";
 
-import { useEffect, useId, useRef, useState } from "react";
+import { useEffect, useId, useRef, useState, useSyncExternalStore } from "react";
 import { QRCodeSVG } from "qrcode.react";
 import { CopyButton } from "@/components/CopyButton";
 import { useFocusTrap } from "@/lib/useFocusTrap";
 
+// Open modals, outermost first. Only the top one handles Escape and traps Tab.
+const modalStack: string[] = [];
+const stackListeners = new Set<() => void>();
+
+function notifyStack() {
+  stackListeners.forEach((listener) => listener());
+}
+
+function subscribeStack(listener: () => void) {
+  stackListeners.add(listener);
+  return () => {
+    stackListeners.delete(listener);
+  };
+}
+
+function useIsTopModal(id: string) {
+  return useSyncExternalStore(
+    subscribeStack,
+    () => modalStack[modalStack.length - 1] === id,
+    () => false,
+  );
+}
+
 export function Modal({
   title,
   onClose,
@@ -16,16 +39,27 @@ export function Modal({
 }) {
   const titleId = useId();
   const panelRef = useRef<HTMLDivElement>(null);
-  useFocusTrap(panelRef);
+  const isTop = useIsTopModal(titleId);
+  useFocusTrap(panelRef, isTop);
+
+  useEffect(() => {
+    modalStack.push(titleId);
+    notifyStack();
+    return () => {
+      modalStack.splice(modalStack.indexOf(titleId), 1);
+      notifyStack();
+    };
+  }, [titleId]);
 
-  // Escape closes, matching native dialog behaviour for keyboard users.
+  // Escape closes, matching native dialog behaviour for keyboard users. Only the top modal reacts.
   useEffect(() => {
+    if (!isTop) return;
     function onKey(e: KeyboardEvent) {
       if (e.key === "Escape") onClose();
     }
     window.addEventListener("keydown", onKey);
     return () => window.removeEventListener("keydown", onKey);
-  }, [onClose]);
+  }, [isTop, onClose]);
 
   return (
     <div
diff --git a/src/lib/useFocusTrap.ts b/src/lib/useFocusTrap.ts
index 1c976f5..9824eba 100644
--- a/src/lib/useFocusTrap.ts
+++ b/src/lib/useFocusTrap.ts
@@ -3,14 +3,21 @@ import { useEffect, useRef, type RefObject } from "react";
 const FOCUSABLE =
   'a[href],button:not([disabled]),input:not([disabled]),select:not([disabled]),textarea:not([disabled]),[tabindex]:not([tabindex="-1"])';
 
-/** Traps Tab focus inside `ref`, focuses it on mount, and restores prior focus on unmount. */
-export function useFocusTrap(ref: RefObject<HTMLElement | null>) {
+/**
+ * Traps Tab focus inside `ref` while `enabled`, focusing it when enabled. Prior focus is
+ * restored on unmount. Nested modals pass `enabled` only for the top one.
+ */
+export function useFocusTrap(ref: RefObject<HTMLElement | null>, enabled = true) {
   const previous = useRef<HTMLElement | null>(null);
 
   useEffect(() => {
-    const root = ref.current;
-    if (!root) return;
     previous.current = document.activeElement as HTMLElement | null;
+    return () => previous.current?.focus?.();
+  }, []);
+
+  useEffect(() => {
+    const root = ref.current;
+    if (!root || !enabled) return;
     const items = () => Array.from(root.querySelectorAll<HTMLElement>(FOCUSABLE));
     (items()[0] ?? root).focus();
 
@@ -34,9 +41,6 @@ export function useFocusTrap(ref: RefObject<HTMLElement | null>) {
       }
     }
     document.addEventListener("keydown", onKey);
-    return () => {
-      document.removeEventListener("keydown", onKey);
-      previous.current?.focus?.();
-    };
-  }, [ref]);
+    return () => document.removeEventListener("keydown", onKey);
+  }, [ref, enabled]);
 }